Jessica Striker. November 10, 2015

Size: px
Start display at page:

Download "Jessica Striker. November 10, 2015"

Transcription

1 Resonance in dynamical algebraic combinatorics Jessica Striker joint work with Kevin Dilks (NDSU) and Oliver Pechenik (UIUC) North Dakota State University November 10, 2015 J. Striker (NDSU) Resonance in DAC November 10, / 65

2 Resonance in dynamical algebraic combinatorics 1 Resonance defined 2 Resonance of gyration 3 Resonance of K-promotion 4 Resonance of rowmotion 5 Resonance conjectures J. Striker (NDSU) Resonance in DAC November 10, / 65

3 Resonance in dynamical algebraic combinatorics 1 Resonance defined 2 Resonance of gyration 3 Resonance of K-promotion 4 Resonance of rowmotion 5 Resonance conjectures J. Striker (NDSU) Resonance in DAC November 10, / 65

4 Resonance in musical instruments J. Striker (NDSU) Resonance in DAC November 10, / 65

5 Resonance in differential equations J. Striker (NDSU) Resonance in DAC November 10, / 65

6 Resonance in dynamical algebraic combinatorics J. Striker (NDSU) Resonance in DAC November 10, / 65

7 Resonance in dynamical algebraic combinatorics What is dynamical algebraic combinatorics? J. Striker (NDSU) Resonance in DAC November 10, / 65

8 Resonance in dynamical algebraic combinatorics J. Striker (NDSU) Resonance in DAC November 10, / 65

9 Resonance in dynamical algebraic combinatorics Definition Dynamical algebraic combinatorics is the study of actions on objects important in algebraic combinatorics. J. Striker (NDSU) Resonance in DAC November 10, / 65

10 Resonance in dynamical algebraic combinatorics Definition Dynamical algebraic combinatorics is the study of actions on objects important in algebraic combinatorics. Compose local actions to get interesting global actions. Toy example: (12)(23)(34)(45)(56) = (123456) Examples of interesting actions in algebraic combinatorics: Gyration on alternating sign matrices Promotion on (standard and increasing) tableaux Rowmotion on order ideals of a poset J. Striker (NDSU) Resonance in DAC November 10, / 65

11 Resonance in dynamical algebraic combinatorics Definition (Dilks, Pechenik, Striker 2015+) Let G = g be a cyclic group acting on a set X, C ω = c a cyclic group of order ω acting on a set Y, and f : X Y. If c f (x) = f (g x) for all x X, we say the triple (X, G, f ) exhibits resonance with frequency ω. X g X f f Y c Y J. Striker (NDSU) Resonance in DAC November 10, / 65

12 Resonance in dynamical algebraic combinatorics Definition (Dilks, Pechenik, Striker 2015+) Let G = g be a cyclic group acting on a set X, C ω = c a cyclic group of order ω acting on a set Y, and f : X Y. If c f (x) = f (g x) for all x X, we say the triple (X, G, f ) exhibits resonance with frequency ω. X g X f f Y c Y An example - gyration on alternating sign matrices J. Striker (NDSU) Resonance in DAC November 10, / 65

13 Resonance in dynamical algebraic combinatorics 1 Resonance defined 2 Resonance of gyration 3 Resonance of K-promotion 4 Resonance of rowmotion 5 Resonance conjectures J. Striker (NDSU) Resonance in DAC November 10, / 65

14 Alternating sign matrix definition Definition Alternating sign matrices (ASMs) are square matrices with the following properties: entries {0, 1, 1} each row and each column sums to 1 nonzero entries alternate in sign along a row/column J. Striker (NDSU) Resonance in DAC November 10, / 65

15 Alternating sign matrices J. Striker (NDSU) Resonance in DAC November 10, / 65

16 Alternating sign matrices fully-packed loops J. Striker (NDSU) Resonance in DAC November 10, / 65

17 Fully-packed loops J. Striker (NDSU) Resonance in DAC November 10, / 65

18 Fully-packed loops Start with an n n grid. J. Striker (NDSU) Resonance in DAC November 10, / 65

19 Fully-packed loops Add boundary conditions. J. Striker (NDSU) Resonance in DAC November 10, / 65

20 Fully-packed loops Interior vertices adjacent to 2 edges. J. Striker (NDSU) Resonance in DAC November 10, / 65

21 Gyration on fully-packed loops Given a square in the grid, the local move swaps the configurations below and leaves every other edge configuration fixed. J. Striker (NDSU) Resonance in DAC November 10, / 65

22 Gyration on fully-packed loops J. Striker (NDSU) Resonance in DAC November 10, / 65

23 Gyration on fully-packed loops Start with the even squares. J. Striker (NDSU) Resonance in DAC November 10, / 65

24 Gyration on fully-packed loops Apply the local move to all even squares. J. Striker (NDSU) Resonance in DAC November 10, / 65

25 Gyration on fully-packed loops Apply the local move to all even squares. J. Striker (NDSU) Resonance in DAC November 10, / 65

26 Gyration on fully-packed loops Apply the local move to all even squares. J. Striker (NDSU) Resonance in DAC November 10, / 65

27 Gyration on fully-packed loops Now consider the odd squares. J. Striker (NDSU) Resonance in DAC November 10, / 65

28 Gyration on fully-packed loops Apply the local move to all odd squares. J. Striker (NDSU) Resonance in DAC November 10, / 65

29 Gyration on fully-packed loops Apply the local move to all odd squares. J. Striker (NDSU) Resonance in DAC November 10, / 65

30 Gyration on fully-packed loops Apply the local move to all odd squares. J. Striker (NDSU) Resonance in DAC November 10, / 65

31 Gyration on fully-packed loops J. Striker (NDSU) Resonance in DAC November 10, / 65

32 Gyration on fully-packed loops J. Striker (NDSU) Resonance in DAC November 10, / 65

33 Resonance of gyration The following theorem of Wieland gives a remarkable property of gyration. Theorem (B. Wieland 2000) Gyration on an FPL rotates the link pattern by a factor of 2π/2n. We reformulate this theorem into a statement of resonance. Corollary Let f be the map from an ASM thru its FPL to the link pattern. Then, (ASM n, < gyr >, f ) exhibits resonance with frequency 2n. J. Striker (NDSU) Resonance in DAC November 10, / 65

34 Resonance of gyration Corollary Let f be the map from an ASM thru its FPL to the link pattern. Then, (ASM n, < gyr >, f ) exhibits resonance with frequency 2n. ASM n f LP gyr rot ASM n f LP J. Striker (NDSU) Resonance in DAC November 10, / 65

35 A length 4 gyration orbit of 5 5 ASMs J. Striker (NDSU) Resonance in DAC November 10, / 65

36 A 6 6 ASM with gyration orbit of length J. Striker (NDSU) Resonance in DAC November 10, / 65

37 Resonance in dynamical algebraic combinatorics 1 Resonance defined 2 Resonance of gyration 3 Resonance of K-promotion 4 Resonance of rowmotion 5 Resonance conjectures J. Striker (NDSU) Resonance in DAC November 10, / 65

38 Increasing tableaux Definition An increasing tableau of shape λ is a filling of a partition shape λ with positive integers so that labels strictly increase from left to right across rows and from top to bottom down columns. Let Inc q (λ) denote the set of increasing tableaux of shape λ with entries at most q. An increasing tableau in Inc 10 (4, 4, 4, 2): J. Striker (NDSU) Resonance in DAC November 10, / 65

39 K-Promotion on an increasing tableau Delete 1 s Fill and decrement J. Striker (NDSU) Resonance in DAC November 10, / 65

40 Order of promotion on SYT Definition A standard Young tableau of shape λ is an increasing tableau filled with positive integers {1, 2,..., λ }. Let SYT (λ) denote the set of standard Young tableaux of shape λ. Theorem (Haiman 1992) Every element of SYT (λ) for λ a rectangle is fixed by promotion to the power λ. Example: There are SYT of shape (7, 7, 7, 7, 7), but promotion is of order 7 5 = 35. J. Striker (NDSU) Resonance in DAC November 10, / 65

41 Resonance of K-promotion Definition Define the content of an increasing tableau T Inc q (λ) to be the binary sequence Con(T ) = (a 1, a 2,..., a q ), where a i = 1 if i is an entry of T and a i = 0 if it is not. Proposition Let T Inc q (λ). If Con(T ) = (a 1, a 2,..., a q ), then Con(K-Pro(T )) is the cyclic shift (a 2,..., a q, a 1 ). Corollary (Inc q (λ), K-Pro, Con) exhibits resonance with frequency q. J. Striker (NDSU) Resonance in DAC November 10, / 65

42 K-Promotion as a product of involutions Proposition For T Inc q (λ), K-Pro(T ) = K-BK q 1 K-BK 1 (T ) K-BK 3 K-BK J. Striker (NDSU) Resonance in DAC November 10, / 65

43 K-Promotion as a product of involutions J. Striker (NDSU) Resonance in DAC November 10, / 65

44 K-Promotion as a product of involutions J. Striker (NDSU) Resonance in DAC November 10, / 65

45 K-Promotion as a product of involutions J. Striker (NDSU) Resonance in DAC November 10, / 65

46 K-Promotion as a product of involutions J. Striker (NDSU) Resonance in DAC November 10, / 65

47 K-Promotion as a product of involutions J. Striker (NDSU) Resonance in DAC November 10, / 65

48 K-Promotion as a product of involutions J. Striker (NDSU) Resonance in DAC November 10, / 65

49 K-Promotion as a product of involutions J. Striker (NDSU) Resonance in DAC November 10, / 65

50 K-Promotion as a product of involutions J. Striker (NDSU) Resonance in DAC November 10, / 65

51 K-Promotion as a product of involutions J. Striker (NDSU) Resonance in DAC November 10, / 65

52 K-Promotion as a product of involutions J. Striker (NDSU) Resonance in DAC November 10, / 65

53 K-Promotion as a product of involutions J. Striker (NDSU) Resonance in DAC November 10, / 65

54 K-Promotion as a product of involutions J. Striker (NDSU) Resonance in DAC November 10, / 65

55 K-Promotion as a product of involutions J. Striker (NDSU) Resonance in DAC November 10, / 65

56 K-Promotion as a product of involutions J. Striker (NDSU) Resonance in DAC November 10, / 65

57 K-Promotion as a product of involutions J. Striker (NDSU) Resonance in DAC November 10, / 65

58 Resonance in dynamical algebraic combinatorics 1 Resonance defined 2 Resonance of gyration 3 Resonance of K-promotion 4 Resonance of rowmotion 5 Resonance conjectures J. Striker (NDSU) Resonance in DAC November 10, / 65

59 Posets A poset is a partially ordered set. Definition A poset is a set with a partial order that is reflexive, antisymmetric, and transitive. J. Striker (NDSU) Resonance in DAC November 10, / 65

60 Order ideals Definition An order ideal of a poset P is a subset X P such that if y X and z y, then z X. The set of order ideals of P is denoted J(P). J. Striker (NDSU) Resonance in DAC November 10, / 65

61 Rowmotion Definition Let P be a poset, and let X J(P). Then rowmotion, Row(X ), is the order ideal generated by the minimal elements of P not in X. An order ideal X J. Striker (NDSU) Resonance in DAC November 10, / 65

62 Rowmotion Definition Let P be a poset, and let X J(P). Then rowmotion, Row(X ), is the order ideal generated by the minimal elements of P not in X. Find the minimal elements of P not in X J. Striker (NDSU) Resonance in DAC November 10, / 65

63 Rowmotion Definition Let P be a poset, and let X J(P). Then rowmotion, Row(X ), is the order ideal generated by the minimal elements of P not in X. Use them to generate a new order ideal Row(X) J. Striker (NDSU) Resonance in DAC November 10, / 65

64 The order of rowmotion in some nice families Theorem (A. Brouwer and A. Schrijver 1974) The order of rowmotion on J(a b) is a + b. Theorem (P. Cameron and D. Fon-der-Flaass 1995) The order of rowmotion on J(a b 2) is a + b + 1. Theorem (P. Cameron and D. Fon-der-Flaass 1995) If a + b + c 1 is prime and c > ab a b + 1, then the cardinality of every orbit of rowmotion on J(a b c) is a multiple of a + b + c 1. J. Striker (NDSU) Resonance in DAC November 10, / 65

65 The toggle group Definition For each element e P define its toggle t e : J(P) J(P) as follows. X {e} if e / X and X {e} J(P) t e (X ) = X \ {e} if e X and X \ {e} J(P) X otherwise Definition (P. Cameron and D. Fon-der-Flaass 1995) The toggle group T (J(P)) is the subgroup of the symmetric group S J(P) generated by {t e } e P. J. Striker (NDSU) Resonance in DAC November 10, / 65

66 Rowmotion as a product of toggles Theorem (P. Cameron and D. Fon-der-Flaass 1995) Given any poset P, Row is the toggle group element that toggles the elements in the reverse order of any linear extension, that is, from top to bottom. J. Striker (NDSU) Resonance in DAC November 10, / 65

67 Rowmotion as a product of toggles Theorem (P. Cameron and D. Fon-der-Flaass 1995) Given any poset P, Row is the toggle group element that toggles the elements in the reverse order of any linear extension, that is, from top to bottom. J. Striker (NDSU) Resonance in DAC November 10, / 65

68 Rowmotion as a product of toggles Theorem (P. Cameron and D. Fon-der-Flaass 1995) Given any poset P, Row is the toggle group element that toggles the elements in the reverse order of any linear extension, that is, from top to bottom. J. Striker (NDSU) Resonance in DAC November 10, / 65

69 Rowmotion as a product of toggles Theorem (P. Cameron and D. Fon-der-Flaass 1995) Given any poset P, Row is the toggle group element that toggles the elements in the reverse order of any linear extension, that is, from top to bottom. J. Striker (NDSU) Resonance in DAC November 10, / 65

70 Rowmotion as a product of toggles Theorem (P. Cameron and D. Fon-der-Flaass 1995) Given any poset P, Row is the toggle group element that toggles the elements in the reverse order of any linear extension, that is, from top to bottom. J. Striker (NDSU) Resonance in DAC November 10, / 65

71 Rowmotion as a product of toggles Theorem (P. Cameron and D. Fon-der-Flaass 1995) Given any poset P, Row is the toggle group element that toggles the elements in the reverse order of any linear extension, that is, from top to bottom. J. Striker (NDSU) Resonance in DAC November 10, / 65

72 Rowmotion as a product of toggles Theorem (P. Cameron and D. Fon-der-Flaass 1995) Given any poset P, Row is the toggle group element that toggles the elements in the reverse order of any linear extension, that is, from top to bottom. J. Striker (NDSU) Resonance in DAC November 10, / 65

73 Rowmotion as a product of toggles Theorem (P. Cameron and D. Fon-der-Flaass 1995) Given any poset P, Row is the toggle group element that toggles the elements in the reverse order of any linear extension, that is, from top to bottom. J. Striker (NDSU) Resonance in DAC November 10, / 65

74 Promotion and rowmotion Theorem (N. Williams and S. 2012) In any ranked poset, there is an equivariant bijection between the order ideals under rowmotion (toggle top to bottom) and promotion (toggle left to right). Promotion and rowmotion have the same orbit structure! J. Striker (NDSU) Resonance in DAC November 10, / 65

75 Partition promotion and rowmotion Theorem (A. Brouwer A. Schrijver 1974) The order of rowmotion on J(a b) is a + b. Explanation (as a corollary of the theorem on the previous slide): Corollary (N. Williams and S. 2012) There is an equivariant bijection between the order ideals of [a] [b] under rowmotion and binary words of length a + b with n ones under rotation. {1100, 1001, 0011, 0110} {1010, 0101} J. Striker (NDSU) Resonance in DAC November 10, / 65

76 the resulting words are balanced. Figure 12 translates the boundary path matrices of Figure 11 to balanced words. We show that this bijection is equivariant, using the definition of ψ in Theorem 7.5. The first rule, ψ [ A] = A, 3,9 corresponds to the case when the first column of the boundary path matrix is (0, 0). This column 2,8 can swap with all other columns without violating the boundary path matrix condition, and so it is 3,7 moved to the end of the word under promotion. 5,7 Consider when 0,6 the first column is (1, 0) 2,6. This column can swap with (0, 0) and (1, 0) without violating the boundary path matrix condition, but it cannot swap with (0, 1) or (1, 1) The second rule, ψ [(A 1,5 1)A 2] = A 1(A 3,5 2), corresponds to when the first column is (1, 0) and the first column it encounters 0,4 that it cannot 2,4 swap with is (0, 1). In this case, the (1, 0) remains fixed, Plane partition promotion and rowmotion 4,8 Theorem (P. Cameron D. 1,7 Fon-der-Flaass 1995) 4,6 The order of 1,5 rowmotion on J(a b 2) is a + b + 1. Explanation and the (0,(as 1) isafreecorollary to move to theof end of thetheorem word. ] on a previous slide): [(A 1 )( A 2 )(... )( A k )A k+1 The third rule, ψ 1,3 Theorem (N. Williams and S. 2012) = A 1(A 2 )(... )( A k )( A k+1 ), corresponds to when the first column (1, 0) encounters (1, 1) first. Then the (1, 0) remains and the (1, 1) can swap to the right without violating the boundary path matrix condition until it reaches the first (0, 1) such Figure that 9. the On columns the left to is the [2] left [3] have [4] drawn the same as an number rc poset of 1s of height in the 2. top When and bottom there rows. This (0, There is anare 1) equivariant two then elements continues with to the bijection the end same of position, the word. between the second element J(a is raised; b the 2) position under We now is indicated give an equivariant by a dotted bijection arrow down. from Covering β m,n under relations ψ to noncrossing are drawn partitions with solid of black [n + m + 1] rowmotion into m lines, + and 1 blocks andnoncrossing are under projected rotation. down For partitions as solid i < j, gray if ( lines. in of position On [a the + right ib is + paired are1] the with into order ) ideal in b position + 1 blocks j including and boundary brackets from pathsthe corresponding symbol )( then to irightmost and j areplane in a block partition together. in Figure The10resulting under rotation. noncrossing (covering partition relations will between have exactly layers m are + 1suppressed). blocks because there are m s in the bottom row of the boundary path matrix: each (0, 0) column is replaced by a, which corresponds to a singleton block, and each (1, 0) column becomes a (, which corresponds to the first element in a block. For an example, see Figure 12. It is clear that this bijection is equivariant.. { } ( )( ( )( )), ( )( ( )( )), ( ( )( ) )( ), ( )( )( )( ), ( )( )( )( ), ( )( ( )( ) ), (( )( ) )( ), ( )( ) ( )( ). Figure 10. An orbit of J([2] [3] [4]) under promotion { ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( )} J. Striker Figure (NDSU) 12. The balanced wordsresonance coming from in DAC the boundary path matrices November in Fig-10, / 65

77 Multidimensional promotion and rowmotion Definition A lattice projection of a poset P is an order and rank preserving map π : P Z n, where x y in Z n if and only if the component-wise difference y x is in N n. Definition (K. Dilks, O. Pechenik, S ) Let P be a poset with an n-dimensional lattice projection π, and choose a distinguished vector v = (v 1, v 2,..., v n ), where v j {±1}. Let T i π,v be the product of toggles t x for all elements of the poset x that lie on the affine hyperplane π(x), v = i. Then define Pro π,v =... T 2 π,vt 1 π,vt 0 π,vt 1 π,vt 2 π,v.... J. Striker (NDSU) Resonance in DAC November 10, / 65

78 Multidimensional promotion and rowmotion J. Striker (NDSU) Resonance in DAC November 10, / 65

79 Multidimensional promotion and rowmotion Definition (K. Dilks, O. Pechenik, S ) Let P be a poset with an n-dimensional lattice projection π, and choose a distinguished vector v = (v 1, v 2,..., v n ), where v j {±1}. Let T i π,v be the product of toggles t x for all elements of the poset x that lie on the affine hyperplane π(x), v = i. Then define Pro π,v =... T 2 π,vt 1 π,vt 0 π,vt 1 π,vt 2 π,v.... Proposition (K. Dilks, O. Pechenik, S ) For any finite ranked poset P and lattice projection π, Pro π,(1,1,...,1) = Row. J. Striker (NDSU) Resonance in DAC November 10, / 65

80 Multidimensional promotion and rowmotion Theorem (K. Dilks, O. Pechenik, S ) Let P be a finite poset with an n-dimensional lattice projection π. Let v = (v 1, v 2, v 3,..., v n ) and w = (w 1, w 2, w 3,..., w n ), where v j, w j {±1}. There is an equivariant bijection between J(P) under Pro π,v and J(P) under Pro π,w. J. Striker (NDSU) Resonance in DAC November 10, / 65

81 A bijection between increasing tableaux and plane partitions Theorem (K. Dilks, O. Pechenik, S ) Ψ 3 : J(a b c) Inc a+b+c 1 (a b) gives a bijection between plane partitions inside an a b c box and increasing tableaux of shape a b and entries at most a + b + c 1. J. Striker (NDSU) Resonance in DAC November 10, / 65

82 A bijection between increasing tableaux and plane partitions P = Project to bottom face Rotate Add 1+rank = Ψ 3 (P) J. Striker (NDSU) Resonance in DAC November 10, / 65

83 An equivariant bijection between increasing tableaux and plane partitions Theorem (K. Dilks, O. Pechenik, S ) Ψ 3 intertwines Pro id,(1,1, 1) and K-Pro. That is, the following diagram commutes: J(a b c) Inc a+b+c 1 (a b) Ψ 3 Pro id,(1,1, 1) K-Pro J(a b c) Inc a+b+c 1 (a b) Ψ 3 J. Striker (NDSU) Resonance in DAC November 10, / 65

84 An equivariant bijection between increasing tableaux and plane partitions Theorem (K. Dilks, O. Pechenik, S ) Ψ 3 intertwines Pro id,(1,1, 1) and K-Pro. That is, the following diagram commutes: J(a b c) Inc a+b+c 1 (a b) Ψ 3 Pro id,(1,1, 1) K-Pro Why? J(a b c) Inc a+b+c 1 (a b) Ψ 3 J. Striker (NDSU) Resonance in DAC November 10, / 65

85 Each hyperplane-toggle corresponds to a K-BK i involution J. Striker (NDSU) Resonance in DAC November 10, / 65

86 Corollaries of the equivariant bijection between increasing tableaux and plane partitions Corollary (K. Dilks, O. Pechenik, S ) J(a b c) under Row is in equivariant bijection with Inc a+b+c 1 (a c) under K-Pro. Corollary (K. Dilks, O. Pechenik, S ) (J(a b c), Row, Con Ψ 3 ) exhibits resonance with frequency a + b + c 1. J. Striker (NDSU) Resonance in DAC November 10, / 65

87 More corollaries of the equivariant bijection between increasing tableaux and plane partitions Corollary There are K-Pro-equivariant bijections between the sets Inc a+b+c 1 (a b), Inc a+b+c 1 (a c), and Inc a+b+c 1 (b c). J. Striker (NDSU) Resonance in DAC November 10, / 65

88 J. Striker (NDSU) Resonance in DAC November 10, / 65

89 Even more corollaries of the equivariant bijection between increasing tableaux and plane partitions Corollary There are K-Pro-equivariant bijections between the sets Inc a+b+c 1 (a b), Inc a+b+c 1 (a c), and Inc a+b+c 1 (b c). Corollary The order of K-Pro on Inc a+b (a b) is a + b. Proof. Using the tri-fold symmetry, there is a K-Pro-equivariant bijection between the sets Inc a+b (a b) and Inc a+b (1 a). The result is then immediate. J. Striker (NDSU) Resonance in DAC November 10, / 65

90 Even more corollaries of the equivariant bijection between increasing tableaux and plane partitions Corollary There are K-Pro-equivariant bijections between the sets Inc a+b+c 1 (a b), Inc a+b+c 1 (a c), and Inc a+b+c 1 (b c). Corollary The order of K-Pro on Inc a+b+1 (a b) is a + b + 1. Proof. Using the tri-fold symmetry, there is a K-Pro-equivariant bijection between the sets Inc a+b+1 (a b) and Inc a+b+1 (2 a). The result is then immediate. J. Striker (NDSU) Resonance in DAC November 10, / 65

91 Resonance in dynamical algebraic combinatorics 1 Resonance defined 2 Resonance of gyration 3 Resonance of K-promotion 4 Resonance of rowmotion 5 Resonance conjectures J. Striker (NDSU) Resonance in DAC November 10, / 65

92 Resonance conjectures Conjecture There exists a map f such that (ASM n, superpromotion, f ) exhibits resonance with frequency 3n 2. Conjecture There exists a map f such that (TSSCPP n, rowmotion, f ) exhibits resonance with frequency 3n 2. J. Striker (NDSU) Resonance in DAC November 10, / 65

93 Data supporting these resonance conjectures ASM under SPro TSSCPP under Row n 3n 2 Orbit Size Number of Orbits Orbit Size Number of Orbits k, k > * * J. Striker (NDSU) Resonance in DAC November 10, / 65

94 Resonance in dynamical algebraic combinatorics 1 Resonance defined 2 Resonance of gyration 3 Resonance of K-promotion 4 Resonance of rowmotion 5 Resonance conjectures J. Striker (NDSU) Resonance in DAC November 10, / 65

95 NDSU Math FORWARD K. Dilks, O. Pechenik, and J. Striker, Resonance in orbits of plane partitions, in preparation. J. Striker and N. Williams, Promotion and rowmotion, Eur. J. Combin. 33 (2012), no. 8, J. Striker (NDSU) Resonance in DAC November 10, / 65

Resonance in orbits of plane partitions and increasing tableaux. Jessica Striker North Dakota State University

Resonance in orbits of plane partitions and increasing tableaux. Jessica Striker North Dakota State University Resonance in orbits of plane partitions and increasing tableaux Jessica Striker North Dakota State University joint work with Kevin Dilks (NDSU) and Oliver Pechenik (UIUC) February 19, 2016 J. Striker

More information

Resonance in orbits of plane partitions

Resonance in orbits of plane partitions FPSAC 2016 Vancouver, Canada DMTCS proc. BC, 2016, 383 394 Resonance in orbits of plane partitions Kevin Dilks 1, Oliver Pechenik 2, and Jessica Striker 1 1 Department of Mathematics, North Dakota State

More information

The long way home. Orbits of plane partitions. Oliver Pechenik. University of Michigan. UM Undergraduate Math Club October 2017

The long way home. Orbits of plane partitions. Oliver Pechenik. University of Michigan. UM Undergraduate Math Club October 2017 Taking the long way home Orbits of plane partitions University of Michigan UM Undergraduate Math Club October 2017 Mostly based on joint work with Kevin Dilks and Jessica Striker (NDSU) motion of partitions

More information

The toggle group, homomesy, and the Razumov-Stroganov correspondence

The toggle group, homomesy, and the Razumov-Stroganov correspondence The toggle group, homomesy, and the Razumov-Stroganov correspondence Jessica Striker Department of Mathematics North Dakota State University Fargo, North Dakota, U.S.A. jessica.striker@ndsu.edu Submitted:

More information

Promotion and Rowmotion

Promotion and Rowmotion FPSAC 2012, Nagoya, Japan DMTCS proc. AR, 2012, 273 28 Promotion and Rowmotion Jessica Striker and Nathan Williams School of Mathematics, University of Minnesota, 20 Church St. SE, Minneapolis, MN Abstract.

More information

Orbits of plane partitions of exceptional Lie type

Orbits of plane partitions of exceptional Lie type (University of Michigan) Joint Mathematics Meetings, San Diego January 2018 Based on joint work with Holly Mandel (Berkeley) arxiv:1712.09180 Minuscule posets The minuscule posets are the following 5 families:

More information

A (lattice) path formula for birational rowmotion on a product of two chains

A (lattice) path formula for birational rowmotion on a product of two chains A (lattice) path formula for birational rowmotion on a product of two chains Tom Roby (UConn) Describing joint research with Gregg Musiker (University of Minnesota) Workshop on Computer Algebra in Combinatorics

More information

Dynamical algebraic combinatorics

Dynamical algebraic combinatorics Dynamical algebraic combinatorics organized by James Propp, Tom Roby, Jessica Striker, and Nathan Williams Workshop Summary Topics of the Workshop This workshop centered around dynamical systems arising

More information

MULTI-ORDERED POSETS. Lisa Bishop Department of Mathematics, Occidental College, Los Angeles, CA 90041, United States.

MULTI-ORDERED POSETS. Lisa Bishop Department of Mathematics, Occidental College, Los Angeles, CA 90041, United States. INTEGERS: ELECTRONIC JOURNAL OF COMBINATORIAL NUMBER THEORY 7 (2007), #A06 MULTI-ORDERED POSETS Lisa Bishop Department of Mathematics, Occidental College, Los Angeles, CA 90041, United States lbishop@oxy.edu

More information

Cylindric Young Tableaux and their Properties

Cylindric Young Tableaux and their Properties Cylindric Young Tableaux and their Properties Eric Neyman (Montgomery Blair High School) Mentor: Darij Grinberg (MIT) Fourth Annual MIT PRIMES Conference May 17, 2014 1 / 17 Introduction Young tableaux

More information

More about partitions

More about partitions Partitions 2.4, 3.4, 4.4 02 More about partitions 3 + +, + 3 +, and + + 3 are all the same partition, so we will write the numbers in non-increasing order. We use greek letters to denote partitions, often

More information

Wieland drift for triangular fully packed loop configurations

Wieland drift for triangular fully packed loop configurations Wieland drift for triangular fully packed loop configurations Sabine Beil Ilse Fischer Fakultät für Mathematik Universität Wien Wien, Austria {sabine.beil,ilse.fischer}@univie.ac.at Philippe Nadeau Institut

More information

5-VERTEX MODELS, GELFAND-TSETLIN PATTERNS AND SEMISTANDARD YOUNG TABLEAUX

5-VERTEX MODELS, GELFAND-TSETLIN PATTERNS AND SEMISTANDARD YOUNG TABLEAUX 5-VERTEX MODELS, GELFAND-TSETLIN PATTERNS AND SEMISTANDARD YOUNG TABLEAUX TANTELY A. RAKOTOARISOA 1. Introduction In statistical mechanics, one studies models based on the interconnections between thermodynamic

More information

Square 2-designs/1. 1 Definition

Square 2-designs/1. 1 Definition Square 2-designs Square 2-designs are variously known as symmetric designs, symmetric BIBDs, and projective designs. The definition does not imply any symmetry of the design, and the term projective designs,

More information

PROBLEMS FROM CCCC LIX

PROBLEMS FROM CCCC LIX PROBLEMS FROM CCCC LIX The following is a list of problems from the 59th installment of the Cambridge Combinatorics and Coffee Club, held at the Worldwide Center of Mathematics in Cambridge, MA on February

More information

Supplement to Multiresolution analysis on the symmetric group

Supplement to Multiresolution analysis on the symmetric group Supplement to Multiresolution analysis on the symmetric group Risi Kondor and Walter Dempsey Department of Statistics and Department of Computer Science The University of Chicago risiwdempsey@uchicago.edu

More information

Week 4-5: Generating Permutations and Combinations

Week 4-5: Generating Permutations and Combinations Week 4-5: Generating Permutations and Combinations February 27, 2017 1 Generating Permutations We have learned that there are n! permutations of {1, 2,...,n}. It is important in many instances to generate

More information

A Bijection between Maximal Chains in Fibonacci Posets

A Bijection between Maximal Chains in Fibonacci Posets journal of combinatorial theory, Series A 78, 268279 (1997) article no. TA972764 A Bijection between Maximal Chains in Fibonacci Posets Darla Kremer Murray State University, Murray, Kentucky 42071 and

More information

arxiv: v2 [math.co] 12 Dec 2018

arxiv: v2 [math.co] 12 Dec 2018 WHIRLING INJECTIONS, SURJECTIONS, AND OTHER FUNCTIONS BETWEEN FINITE SETS MICHAEL JOSEPH, JAMES PROPP, AND TOM ROBY arxiv:1711.02411v2 [math.co] 12 Dec 2018 Abstract. This paper analyzes a certain action

More information

Higher Spin Alternating Sign Matrices

Higher Spin Alternating Sign Matrices Higher Spin Alternating Sign Matrices Roger E. Behrend and Vincent A. Knight School of Mathematics, Cardiff University, Cardiff, CF24 4AG, UK behrendr@cardiff.ac.uk, knightva@cardiff.ac.uk Submitted: Aug

More information

Combinatorial Structures

Combinatorial Structures Combinatorial Structures Contents 1 Permutations 1 Partitions.1 Ferrers diagrams....................................... Skew diagrams........................................ Dominance order......................................

More information

Fully Packed Loops Model: Integrability and Combinatorics. Plan

Fully Packed Loops Model: Integrability and Combinatorics. Plan ully Packed Loops Model 1 Fully Packed Loops Model: Integrability and Combinatorics Moscow 05/04 P. Di Francesco, P. Zinn-Justin, Jean-Bernard Zuber, math.co/0311220 J. Jacobsen, P. Zinn-Justin, math-ph/0402008

More information

arxiv: v1 [math.co] 6 Jun 2014

arxiv: v1 [math.co] 6 Jun 2014 WIELAND GYRATION FOR TRIANGULAR FULLY PACKED LOOP CONFIGURATIONS SABINE BEIL, ILSE FISCHER, AND PHILIPPE NADEAU arxiv:1406.1657v1 [math.co] 6 Jun 2014 Abstract. Triangular fully packed loop configurations

More information

An Investigation on an Extension of Mullineux Involution

An Investigation on an Extension of Mullineux Involution An Investigation on an Extension of Mullineux Involution SPUR Final Paper, Summer 06 Arkadiy Frasinich Mentored by Augustus Lonergan Project Suggested By Roman Bezrukavnikov August 3, 06 Abstract In this

More information

arxiv: v1 [math.co] 3 Nov 2014

arxiv: v1 [math.co] 3 Nov 2014 SPARSE MATRICES DESCRIBING ITERATIONS OF INTEGER-VALUED FUNCTIONS BERND C. KELLNER arxiv:1411.0590v1 [math.co] 3 Nov 014 Abstract. We consider iterations of integer-valued functions φ, which have no fixed

More information

Involutions by Descents/Ascents and Symmetric Integral Matrices. Alan Hoffman Fest - my hero Rutgers University September 2014

Involutions by Descents/Ascents and Symmetric Integral Matrices. Alan Hoffman Fest - my hero Rutgers University September 2014 by Descents/Ascents and Symmetric Integral Matrices Richard A. Brualdi University of Wisconsin-Madison Joint work with Shi-Mei Ma: European J. Combins. (to appear) Alan Hoffman Fest - my hero Rutgers University

More information

ALGEBRAIC GEOMETRY I - FINAL PROJECT

ALGEBRAIC GEOMETRY I - FINAL PROJECT ALGEBRAIC GEOMETRY I - FINAL PROJECT ADAM KAYE Abstract This paper begins with a description of the Schubert varieties of a Grassmannian variety Gr(k, n) over C Following the technique of Ryan [3] for

More information

Birational Rowmotion: order, homomesy, and cluster connections

Birational Rowmotion: order, homomesy, and cluster connections Birational Rowmotion: order, homomesy, and cluster connections Tom Roby (University of Connecticut) Describing joint research with Darij Grinberg Combinatorics Seminar University of Minnesota Minneapolis,

More information

Coxeter-Knuth Classes and a Signed Little Bijection

Coxeter-Knuth Classes and a Signed Little Bijection Coxeter-Knuth Classes and a Signed Little Bijection Sara Billey University of Washington Based on joint work with: Zachary Hamaker, Austin Roberts, and Benjamin Young. UC Berkeley, February, 04 Outline

More information

Enumeration on row-increasing tableaux of shape 2 n

Enumeration on row-increasing tableaux of shape 2 n Enumeration on row-increasing tableaux of shape 2 n Rosena R. X. Du East China Normal University, Shanghai, China Joint work with Xiaojie Fan and Yue Zhao Shanghai Jiaotong University June 25, 2018 2/38

More information

Math 3121, A Summary of Sections 0,1,2,4,5,6,7,8,9

Math 3121, A Summary of Sections 0,1,2,4,5,6,7,8,9 Math 3121, A Summary of Sections 0,1,2,4,5,6,7,8,9 Section 0. Sets and Relations Subset of a set, B A, B A (Definition 0.1). Cartesian product of sets A B ( Defintion 0.4). Relation (Defintion 0.7). Function,

More information

Noncrossing partitions, toggles, and homomesies

Noncrossing partitions, toggles, and homomesies Noncrossing partitions, toggles, and homomesies The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Citation As Published Publisher Einstein,

More information

Spectra of Semidirect Products of Cyclic Groups

Spectra of Semidirect Products of Cyclic Groups Spectra of Semidirect Products of Cyclic Groups Nathan Fox 1 University of Minnesota-Twin Cities Abstract The spectrum of a graph is the set of eigenvalues of its adjacency matrix A group, together with

More information

AUTOMORPHISM GROUPS AND SPECTRA OF CIRCULANT GRAPHS

AUTOMORPHISM GROUPS AND SPECTRA OF CIRCULANT GRAPHS AUTOMORPHISM GROUPS AND SPECTRA OF CIRCULANT GRAPHS MAX GOLDBERG Abstract. We explore ways to concisely describe circulant graphs, highly symmetric graphs with properties that are easier to generalize

More information

Crossings and Nestings in Tangled Diagrams

Crossings and Nestings in Tangled Diagrams Crossings and Nestings in Tangled Diagrams William Y. C. Chen 1, Jing Qin 2 and Christian M. Reidys 3 Center for Combinatorics, LPMC-TJKLC Nankai University, Tianjin 300071, P. R. China 1 chen@nankai.edu.cn,

More information

What is a semigroup? What is a group? What is the difference between a semigroup and a group?

What is a semigroup? What is a group? What is the difference between a semigroup and a group? The second exam will be on Thursday, July 5, 2012. The syllabus will be Sections IV.5 (RSA Encryption), III.1, III.2, III.3, III.4 and III.8, III.9, plus the handout on Burnside coloring arguments. Of

More information

The power graph of a finite group, II

The power graph of a finite group, II The power graph of a finite group, II Peter J. Cameron School of Mathematical Sciences Queen Mary, University of London Mile End Road London E1 4NS, U.K. Abstract The directed power graph of a group G

More information

Isomorphisms between pattern classes

Isomorphisms between pattern classes Journal of Combinatorics olume 0, Number 0, 1 8, 0000 Isomorphisms between pattern classes M. H. Albert, M. D. Atkinson and Anders Claesson Isomorphisms φ : A B between pattern classes are considered.

More information

Poset and Polytope Perspectives On Alternating Sign Matrices

Poset and Polytope Perspectives On Alternating Sign Matrices Poset and Polytope Perspectives On Alternating Sign Matrices A DISSERTATION SUBMITTED TO THE FACULTY OF THE GRADUATE SCHOOL OF THE UNIVERSITY OF MINNESOTA BY Jessica Palencia Striker IN PARTIAL FULFILLMENT

More information

A DECOMPOSITION OF SCHUR FUNCTIONS AND AN ANALOGUE OF THE ROBINSON-SCHENSTED-KNUTH ALGORITHM

A DECOMPOSITION OF SCHUR FUNCTIONS AND AN ANALOGUE OF THE ROBINSON-SCHENSTED-KNUTH ALGORITHM A DECOMPOSITION OF SCHUR FUNCTIONS AND AN ANALOGUE OF THE ROBINSON-SCHENSTED-KNUTH ALGORITHM S. MASON Abstract. We exhibit a weight-preserving bijection between semi-standard Young tableaux and semi-skyline

More information

Standard Young Tableaux Old and New

Standard Young Tableaux Old and New Standard Young Tableaux Old and New Ron Adin and Yuval Roichman Department of Mathematics Bar-Ilan University Workshop on Group Theory in Memory of David Chillag Technion, Haifa, Oct. 14 1 2 4 3 5 7 6

More information

GROUP THEORY PRIMER. New terms: tensor, rank k tensor, Young tableau, Young diagram, hook, hook length, factors over hooks rule

GROUP THEORY PRIMER. New terms: tensor, rank k tensor, Young tableau, Young diagram, hook, hook length, factors over hooks rule GROUP THEORY PRIMER New terms: tensor, rank k tensor, Young tableau, Young diagram, hook, hook length, factors over hooks rule 1. Tensor methods for su(n) To study some aspects of representations of a

More information

Definition: A binary relation R from a set A to a set B is a subset R A B. Example:

Definition: A binary relation R from a set A to a set B is a subset R A B. Example: Chapter 9 1 Binary Relations Definition: A binary relation R from a set A to a set B is a subset R A B. Example: Let A = {0,1,2} and B = {a,b} {(0, a), (0, b), (1,a), (2, b)} is a relation from A to B.

More information

Combinatorics of non-associative binary operations

Combinatorics of non-associative binary operations Combinatorics of non-associative binary operations Jia Huang University of Nebraska at Kearney E-mail address: huangj2@unk.edu December 26, 2017 This is joint work with Nickolas Hein (Benedictine College),

More information

Note that a unit is unique: 1 = 11 = 1. Examples: Nonnegative integers under addition; all integers under multiplication.

Note that a unit is unique: 1 = 11 = 1. Examples: Nonnegative integers under addition; all integers under multiplication. Algebra fact sheet An algebraic structure (such as group, ring, field, etc.) is a set with some operations and distinguished elements (such as 0, 1) satisfying some axioms. This is a fact sheet with definitions

More information

0 Sets and Induction. Sets

0 Sets and Induction. Sets 0 Sets and Induction Sets A set is an unordered collection of objects, called elements or members of the set. A set is said to contain its elements. We write a A to denote that a is an element of the set

More information

Counting chains in noncrossing partition lattices

Counting chains in noncrossing partition lattices Counting chains in noncrossing partition lattices Nathan Reading NC State University NCSU Algebra Seminar, November 16, 2007 1 Counting chains in noncrossing partition lattices Classical noncrossing partitions

More information

Permutation Groups and Transformation Semigroups Lecture 2: Semigroups

Permutation Groups and Transformation Semigroups Lecture 2: Semigroups Permutation Groups and Transformation Semigroups Lecture 2: Semigroups Peter J. Cameron Permutation Groups summer school, Marienheide 18 22 September 2017 I am assuming that you know what a group is, but

More information

INTERVAL PARTITIONS AND STANLEY DEPTH

INTERVAL PARTITIONS AND STANLEY DEPTH INTERVAL PARTITIONS AND STANLEY DEPTH CSABA BIRÓ, DAVID M. HOWARD, MITCHEL T. KELLER, WILLIAM. T. TROTTER, AND STEPHEN J. YOUNG Abstract. In this paper, we answer a question posed by Herzog, Vladoiu, and

More information

5 Group theory. 5.1 Binary operations

5 Group theory. 5.1 Binary operations 5 Group theory This section is an introduction to abstract algebra. This is a very useful and important subject for those of you who will continue to study pure mathematics. 5.1 Binary operations 5.1.1

More information

Regular and synchronizing transformation monoids

Regular and synchronizing transformation monoids Regular and synchronizing transformation monoids Peter J. Cameron NBSAN, York 23 November 2011 Mathematics may be defined as the subject in which we never know what we are talking about, nor whether what

More information

Tactical Decompositions of Steiner Systems and Orbits of Projective Groups

Tactical Decompositions of Steiner Systems and Orbits of Projective Groups Journal of Algebraic Combinatorics 12 (2000), 123 130 c 2000 Kluwer Academic Publishers. Manufactured in The Netherlands. Tactical Decompositions of Steiner Systems and Orbits of Projective Groups KELDON

More information

Patterns in Standard Young Tableaux

Patterns in Standard Young Tableaux Patterns in Standard Young Tableaux Sara Billey University of Washington Slides: math.washington.edu/ billey/talks Based on joint work with: Matjaž Konvalinka and Joshua Swanson 6th Encuentro Colombiano

More information

Section Summary. Relations and Functions Properties of Relations. Combining Relations

Section Summary. Relations and Functions Properties of Relations. Combining Relations Chapter 9 Chapter Summary Relations and Their Properties n-ary Relations and Their Applications (not currently included in overheads) Representing Relations Closures of Relations (not currently included

More information

6 Cosets & Factor Groups

6 Cosets & Factor Groups 6 Cosets & Factor Groups The course becomes markedly more abstract at this point. Our primary goal is to break apart a group into subsets such that the set of subsets inherits a natural group structure.

More information

arxiv: v1 [math.co] 2 Dec 2008

arxiv: v1 [math.co] 2 Dec 2008 An algorithmic Littlewood-Richardson rule arxiv:08.0435v [math.co] Dec 008 Ricky Ini Liu Massachusetts Institute of Technology Cambridge, Massachusetts riliu@math.mit.edu June, 03 Abstract We introduce

More information

Multiplicity Free Expansions of Schur P-Functions

Multiplicity Free Expansions of Schur P-Functions Annals of Combinatorics 11 (2007) 69-77 0218-0006/07/010069-9 DOI 10.1007/s00026-007-0306-1 c Birkhäuser Verlag, Basel, 2007 Annals of Combinatorics Multiplicity Free Expansions of Schur P-Functions Kristin

More information

Counting matrices over finite fields

Counting matrices over finite fields Counting matrices over finite fields Steven Sam Massachusetts Institute of Technology September 30, 2011 1/19 Invertible matrices F q is a finite field with q = p r elements. [n] = 1 qn 1 q = qn 1 +q n

More information

Enumeration Schemes for Words Avoiding Permutations

Enumeration Schemes for Words Avoiding Permutations Enumeration Schemes for Words Avoiding Permutations Lara Pudwell November 27, 2007 Abstract The enumeration of permutation classes has been accomplished with a variety of techniques. One wide-reaching

More information

CSC Discrete Math I, Spring Relations

CSC Discrete Math I, Spring Relations CSC 125 - Discrete Math I, Spring 2017 Relations Binary Relations Definition: A binary relation R from a set A to a set B is a subset of A B Note that a relation is more general than a function Example:

More information

Domino tilings with barriers. In memory of Gian-Carlo Rota

Domino tilings with barriers. In memory of Gian-Carlo Rota Domino tilings with barriers In memory of Gian-Carlo Rota James Propp Richard Stanley University of Wisconsin, Madison, WI 53706 Massachusetts Institute of Technology, Cambridge, MA 02139 In this paper,

More information

Equality of P-partition Generating Functions

Equality of P-partition Generating Functions Bucknell University Bucknell Digital Commons Honors Theses Student Theses 2011 Equality of P-partition Generating Functions Ryan Ward Bucknell University Follow this and additional works at: https://digitalcommons.bucknell.edu/honors_theses

More information

NOTES ABOUT SATURATED CHAINS IN THE DYCK PATH POSET. 1. Basic Definitions

NOTES ABOUT SATURATED CHAINS IN THE DYCK PATH POSET. 1. Basic Definitions NOTES ABOUT SATURATED CHAINS IN THE DYCK PATH POSET JENNIFER WOODCOCK 1. Basic Definitions Dyck paths are one of the many combinatorial objects enumerated by the Catalan numbers, sequence A000108 in [2]:

More information

arxiv: v2 [math.co] 9 Aug 2018

arxiv: v2 [math.co] 9 Aug 2018 ORBITS OF PLANE PARTITIONS OF EXCEPTIONAL LIE TYPE HOLLY MANDEL AND OLIVER PECHENIK arxiv:1712.09180v2 [math.co] 9 Aug 2018 Abstract. For each minuscule flag variety X, there is a corresponding minuscule

More information

Examples of Groups

Examples of Groups Examples of Groups 8-23-2016 In this section, I ll look at some additional examples of groups. Some of these will be discussed in more detail later on. In many of these examples, I ll assume familiar things

More information

Groups of Prime Power Order with Derived Subgroup of Prime Order

Groups of Prime Power Order with Derived Subgroup of Prime Order Journal of Algebra 219, 625 657 (1999) Article ID jabr.1998.7909, available online at http://www.idealibrary.com on Groups of Prime Power Order with Derived Subgroup of Prime Order Simon R. Blackburn*

More information

Homomesy of Alignments in Perfect Matchings

Homomesy of Alignments in Perfect Matchings Homomesy of Alignments in Perfect Matchings Ingrid Zhang under the direction of Sam Hopkins Department of Mathematics Massachusetts Institute of Technology Research Science Institute July 0, 2014 Abstract

More information

Edinburgh, December 2009

Edinburgh, December 2009 From totally nonnegative matrices to quantum matrices and back, via Poisson geometry Edinburgh, December 2009 Joint work with Ken Goodearl and Stéphane Launois Papers available at: http://www.maths.ed.ac.uk/~tom/preprints.html

More information

Lecture 20 FUNDAMENTAL Theorem of Finitely Generated Abelian Groups (FTFGAG)

Lecture 20 FUNDAMENTAL Theorem of Finitely Generated Abelian Groups (FTFGAG) Lecture 20 FUNDAMENTAL Theorem of Finitely Generated Abelian Groups (FTFGAG) Warm up: 1. Let n 1500. Find all sequences n 1 n 2... n s 2 satisfying n i 1 and n 1 n s n (where s can vary from sequence to

More information

Ilse Fischer. A SYMMETRY THEOREM ON A MODIFIED JEU DE TAQUIN arxiv:math/ v1 [math.co] 23 Dec 2001

Ilse Fischer. A SYMMETRY THEOREM ON A MODIFIED JEU DE TAQUIN arxiv:math/ v1 [math.co] 23 Dec 2001 A SYMMETRY THEOREM ON A MODIFIED JEU DE TAQUIN arxiv:math/01163v1 [math.co] 3 Dec 001 Ilse Fischer Institut für Mathematik der Universität Klagenfurt Universitätsstrasse 65-67 A-900 Klagenfurt Austria.

More information

arxiv: v3 [math.co] 4 Apr 2014

arxiv: v3 [math.co] 4 Apr 2014 CYCLIC SIEVING OF INCREASING TABLEAUX AND SMALL SCHRÖDER PATHS OLIVER PECHENIK arxiv:1209.1355v3 [math.co] 4 Apr 2014 Abstract. An increasing tableau is a semistandard tableau with strictly increasing

More information

TROPICAL BRILL-NOETHER THEORY

TROPICAL BRILL-NOETHER THEORY TROPICAL BRILL-NOETHER THEORY 5. Special divisors on a chain of loops For this lecture, we will study special divisors a generic chain of loops. specifically, when g, r, d are nonnegative numbers satisfying

More information

Partitions and permutations

Partitions and permutations Partitions and permutations Peter J. Cameron School of Mathematical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS, UK Abstract With any permutation g of a set Ω is associated

More information

(1.1) In particular, ψ( q 1, m 1 ; ; q N, m N ) 2 is the probability to find the first particle

(1.1) In particular, ψ( q 1, m 1 ; ; q N, m N ) 2 is the probability to find the first particle Chapter 1 Identical particles 1.1 Distinguishable particles The Hilbert space of N has to be a subspace H = N n=1h n. Observables Ân of the n-th particle are self-adjoint operators of the form 1 1 1 1

More information

Rational Catalan Combinatorics

Rational Catalan Combinatorics Rational Catalan Combinatorics Eugene Gorsky UC Davis Bay Area Discrete Math Day October 17, 2015 Counting Dyck paths Catalan numbers The Catalan number is the number of Dyck paths, that is, lattice paths

More information

Definitions. Notations. Injective, Surjective and Bijective. Divides. Cartesian Product. Relations. Equivalence Relations

Definitions. Notations. Injective, Surjective and Bijective. Divides. Cartesian Product. Relations. Equivalence Relations Page 1 Definitions Tuesday, May 8, 2018 12:23 AM Notations " " means "equals, by definition" the set of all real numbers the set of integers Denote a function from a set to a set by Denote the image of

More information

The Gaussian coefficient revisited

The Gaussian coefficient revisited The Gaussian coefficient revisited Richard EHRENBORG and Margaret A. READDY Abstract We give new -(1+)-analogue of the Gaussian coefficient, also now as the -binomial which, lie the original -binomial

More information

The symmetric group action on rank-selected posets of injective words

The symmetric group action on rank-selected posets of injective words The symmetric group action on rank-selected posets of injective words Christos A. Athanasiadis Department of Mathematics University of Athens Athens 15784, Hellas (Greece) caath@math.uoa.gr October 28,

More information

John B. Fraleigh, A first course in Abstract Algebra, 5th edition, Addison-Wesley.

John B. Fraleigh, A first course in Abstract Algebra, 5th edition, Addison-Wesley. MATH222 ALGEBRAIC METHODS I This subject introduces the study of fundamental algebraic structures and the methods of abstract algebra which pervade much of modern mathematics. One of the important aims

More information

Partitions and Algebraic Structures

Partitions and Algebraic Structures CHAPTER A Partitions and Algebraic Structures In this chapter, we introduce partitions of natural numbers and the Ferrers diagrams. The algebraic structures of partitions such as addition, multiplication

More information

Matrices and Vectors

Matrices and Vectors Matrices and Vectors James K. Peterson Department of Biological Sciences and Department of Mathematical Sciences Clemson University November 11, 2013 Outline 1 Matrices and Vectors 2 Vector Details 3 Matrix

More information

= i 0. a i q i. (1 aq i ).

= i 0. a i q i. (1 aq i ). SIEVED PARTITIO FUCTIOS AD Q-BIOMIAL COEFFICIETS Fran Garvan* and Dennis Stanton** Abstract. The q-binomial coefficient is a polynomial in q. Given an integer t and a residue class r modulo t, a sieved

More information

Maximal supports and Schur-positivity among connected skew shapes

Maximal supports and Schur-positivity among connected skew shapes Maximal supports and Schur-positivity among connected skew shapes Peter R. W. McNamara a, Stephanie van Willigenburg b,1 a Department of Mathematics, Bucknell University, Lewisburg, PA 17837, USA b Department

More information

ON SOME FACTORIZATION FORMULAS OF K-k-SCHUR FUNCTIONS

ON SOME FACTORIZATION FORMULAS OF K-k-SCHUR FUNCTIONS ON SOME FACTORIZATION FORMULAS OF K-k-SCHUR FUNCTIONS MOTOKI TAKIGIKU Abstract. We give some new formulas about factorizations of K-k-Schur functions, analogous to the k-rectangle factorization formula

More information

Generating Permutations and Combinations

Generating Permutations and Combinations Generating Permutations and Combinations March 0, 005 Generating Permutations We have learned that there are n! permutations of {,,, n} It is important in many instances to generate a list of such permutations

More information

Problem 1. Let f n (x, y), n Z, be the sequence of rational functions in two variables x and y given by the initial conditions.

Problem 1. Let f n (x, y), n Z, be the sequence of rational functions in two variables x and y given by the initial conditions. 18.217 Problem Set (due Monday, December 03, 2018) Solve as many problems as you want. Turn in your favorite solutions. You can also solve and turn any other claims that were given in class without proofs,

More information

The Littlewood-Richardson Rule

The Littlewood-Richardson Rule REPRESENTATIONS OF THE SYMMETRIC GROUP The Littlewood-Richardson Rule Aman Barot B.Sc.(Hons.) Mathematics and Computer Science, III Year April 20, 2014 Abstract We motivate and prove the Littlewood-Richardson

More information

On the singular elements of a semisimple Lie algebra and the generalized Amitsur-Levitski Theorem

On the singular elements of a semisimple Lie algebra and the generalized Amitsur-Levitski Theorem On the singular elements of a semisimple Lie algebra and the generalized Amitsur-Levitski Theorem Bertram Kostant, MIT Conference on Representations of Reductive Groups Salt Lake City, Utah July 10, 2013

More information

Combinatorial bases for representations. of the Lie superalgebra gl m n

Combinatorial bases for representations. of the Lie superalgebra gl m n Combinatorial bases for representations of the Lie superalgebra gl m n Alexander Molev University of Sydney Gelfand Tsetlin bases for gln Gelfand Tsetlin bases for gl n Finite-dimensional irreducible representations

More information

DISTINGUISHING PARTITIONS AND ASYMMETRIC UNIFORM HYPERGRAPHS

DISTINGUISHING PARTITIONS AND ASYMMETRIC UNIFORM HYPERGRAPHS DISTINGUISHING PARTITIONS AND ASYMMETRIC UNIFORM HYPERGRAPHS M. N. ELLINGHAM AND JUSTIN Z. SCHROEDER In memory of Mike Albertson. Abstract. A distinguishing partition for an action of a group Γ on a set

More information

11 Block Designs. Linear Spaces. Designs. By convention, we shall

11 Block Designs. Linear Spaces. Designs. By convention, we shall 11 Block Designs Linear Spaces In this section we consider incidence structures I = (V, B, ). always let v = V and b = B. By convention, we shall Linear Space: We say that an incidence structure (V, B,

More information

A note on quantum products of Schubert classes in a Grassmannian

A note on quantum products of Schubert classes in a Grassmannian J Algebr Comb (2007) 25:349 356 DOI 10.1007/s10801-006-0040-5 A note on quantum products of Schubert classes in a Grassmannian Dave Anderson Received: 22 August 2006 / Accepted: 14 September 2006 / Published

More information

Reduced words and a formula of Macdonald

Reduced words and a formula of Macdonald Reduced words and a formula of Macdonald Sara Billey University of Washington Based on joint work with: Alexander Holroyd and Benjamin Young preprint arxiv:70.096 Graduate Student Combinatorics Conference

More information

A multiplicative deformation of the Möbius function for the poset of partitions of a multiset

A multiplicative deformation of the Möbius function for the poset of partitions of a multiset Contemporary Mathematics A multiplicative deformation of the Möbius function for the poset of partitions of a multiset Patricia Hersh and Robert Kleinberg Abstract. The Möbius function of a partially ordered

More information

On the Shadow Geometries of W (23, 16)

On the Shadow Geometries of W (23, 16) On the of W (23, 16) Assaf Goldberger 1 Yossi Strassler 2 Giora Dula 3 1 School of Mathematical Sciences Tel-Aviv University 2 Dan Yishay 3 Department of Computer Science and Mathematics Netanya College

More information

Catalan numbers, parking functions, and invariant theory

Catalan numbers, parking functions, and invariant theory Catalan numbers, parking functions, and invariant theory Vic Reiner Univ. of Minnesota CanaDAM Memorial University, Newfoundland June 10, 2013 Outline 1 Catalan numbers and objects 2 Parking functions

More information

Central Groupoids, Central Digraphs, and Zero-One Matrices A Satisfying A 2 = J

Central Groupoids, Central Digraphs, and Zero-One Matrices A Satisfying A 2 = J Central Groupoids, Central Digraphs, and Zero-One Matrices A Satisfying A 2 = J Frank Curtis, John Drew, Chi-Kwong Li, and Daniel Pragel September 25, 2003 Abstract We study central groupoids, central

More information

Extended 1-perfect additive codes

Extended 1-perfect additive codes Extended 1-perfect additive codes J.Borges, K.T.Phelps, J.Rifà 7/05/2002 Abstract A binary extended 1-perfect code of length n + 1 = 2 t is additive if it is a subgroup of Z α 2 Zβ 4. The punctured code

More information

DIFFERENTIAL POSETS SIMON RUBINSTEIN-SALZEDO

DIFFERENTIAL POSETS SIMON RUBINSTEIN-SALZEDO DIFFERENTIAL POSETS SIMON RUBINSTEIN-SALZEDO Abstract. In this paper, we give a sampling of the theory of differential posets, including various topics that excited me. Most of the material is taken from

More information

Exercises for Discrete Maths

Exercises for Discrete Maths Exercises for Discrete Maths Discrete Maths Rosella Gennari http://www.inf.unibz.it/~gennari gennari@inf.unibz.it Computer Science Free University of Bozen-Bolzano Disclaimer. The course exercises are

More information