Lecture 1: Gröbner Bases and Border Bases
|
|
- Felix Bailey
- 6 years ago
- Views:
Transcription
1 Lecture 1: Gröbner Bases and Border Bases The Schizophrenic Lecture Martin Kreuzer Fakultät für Informatik und Mathematik Universität Passau uni-passau.de Sophus Lie Center Nordfjordeid June 15,
2 Contents 2
3 Contents 1. Gröbner Bases 2-a
4 Contents 1. Gröbner Bases 2. Border Bases 2-b
5 Contents 1. Gröbner Bases 2. Border Bases 3. Properties of GB and BB 2-c
6 Contents 1. Gröbner Bases 2. Border Bases 3. Properties of GB and BB 4. Division Algorithms 2-d
7 Contents 1. Gröbner Bases 2. Border Bases 3. Properties of GB and BB 4. Division Algorithms 5. Neighbors 2-e
8 Contents 1. Gröbner Bases 2. Border Bases 3. Properties of GB and BB 4. Division Algorithms 5. Neighbors 6. The Buchberger Criterion 2-f
9 1 Gröbner Bases Before you criticize someone you should walk a mile in their shoes. 3
10 1 Gröbner Bases Before you criticize someone you should walk a mile in their shoes. In this way, when you criticize them, 3-a
11 1 Gröbner Bases Before you criticize someone you should walk a mile in their shoes. In this way, when you criticize them, you are a mile away 3-b
12 1 Gröbner Bases Before you criticize someone you should walk a mile in their shoes. In this way, when you criticize them, you are a mile away and you have their shoes. 3-c
13 1 Gröbner Bases Before you criticize someone you should walk a mile in their shoes. In this way, when you criticize them, you are a mile away and you have their shoes. K field P = K[x 1,...,x n ] polynomial ring over K 3-d
14 1 Gröbner Bases Before you criticize someone you should walk a mile in their shoes. In this way, when you criticize them, you are a mile away and you have their shoes. K field P = K[x 1,...,x n ] polynomial ring over K T n = {x α 1 1 xα n n α i 0} monoid of terms σ term ordering on T n (complete, multiplicative well-ordering) 3-e
15 Definition of Gröbner Bases (a) Every f P \ {0} has a unique representation f = c 1 t c s t s with c i K \ {0} and t i T n such that t 1 > σ > σ t s. The term LT σ (f) = t 1 is called the leading term of f and LC σ (f) = c 1 is the leading coefficient of f. 4
16 Definition of Gröbner Bases (a) Every f P \ {0} has a unique representation f = c 1 t c s t s with c i K \ {0} and t i T n such that t 1 > σ > σ t s. The term LT σ (f) = t 1 is called the leading term of f and LC σ (f) = c 1 is the leading coefficient of f. (b) For an ideal I P, we let LT σ (I) = LT σ (f) f I \ {0} and call it the leading term ideal of I. 4-a
17 Definition of Gröbner Bases (a) Every f P \ {0} has a unique representation f = c 1 t c s t s with c i K \ {0} and t i T n such that t 1 > σ > σ t s. The term LT σ (f) = t 1 is called the leading term of f and LC σ (f) = c 1 is the leading coefficient of f. (b) For an ideal I P, we let LT σ (I) = LT σ (f) f I \ {0} and call it the leading term ideal of I. (c) A set of polynomials f 1,...,f s I is called a σ-gröbner basis of I if LT σ (I) = LT σ (f 1 ),...,LT σ (f s ). 4-b
18 2 Border Bases Given the choice between two theories, 5
19 2 Border Bases Given the choice between two theories, take the one which is funnier. 5-a
20 2 Border Bases Given the choice between two theories, take the one which is funnier. I P zero-dimensional polynomial ideal (i.e. dim K (P/I) < ) 5-b
21 2 Border Bases Given the choice between two theories, take the one which is funnier. I P zero-dimensional polynomial ideal (i.e. dim K (P/I) < ) Open Problem: Give a good definition of border bases for higher-dimensional ideals and generalize all results in this and the subsequent lectures! 5-c
22 2 Border Bases Given the choice between two theories, take the one which is funnier. I P zero-dimensional polynomial ideal (i.e. dim K (P/I) < ) Open Problem: Give a good definition of border bases for higher-dimensional ideals and generalize all results in this and the subsequent lectures! Definition 2.1 (a) A (finite) set O T n is called an order ideal if every term dividing a term in O is contained in O. 5-d
23 2 Border Bases Given the choice between two theories, take the one which is funnier. I P zero-dimensional polynomial ideal (i.e. dim K (P/I) < ) Open Problem: Give a good definition of border bases for higher-dimensional ideals and generalize all results in this and the subsequent lectures! Definition 2.1 (a) A (finite) set O T n is called an order ideal if every term dividing a term in O is contained in O. (b) Let O be an order ideal. The set O = (x 1 O x n O) \ O is called the border of O. 5-e
24 Picture of an Order Ideal and its Border 6
25 Picture of an Order Ideal and its Border term in the order ideal term in the border 6-a
26 Definition 2.2 (a) Let O = {t 1,...,t µ } be an order ideal and O = {b 1,...,b ν } its border. A set of polynomials {g 1,...,g ν } I of the form g j = b j µ c ij t i with c ij K and t i O is called an O-border prebasis of I. i=1 7
27 Definition 2.2 (a) Let O = {t 1,...,t µ } be an order ideal and O = {b 1,...,b ν } its border. A set of polynomials {g 1,...,g ν } I of the form g j = b j µ c ij t i with c ij K and t i O is called an O-border prebasis of I. (b) An O-border prebasis of I is called an O-border basis of I if the residue classes of the terms in O are a K-vector space basis of P/I. i=1 7-a
28 Definition 2.2 (a) Let O = {t 1,...,t µ } be an order ideal and O = {b 1,...,b ν } its border. A set of polynomials {g 1,...,g ν } I of the form g j = b j µ c ij t i with c ij K and t i O is called an O-border prebasis of I. (b) An O-border prebasis of I is called an O-border basis of I if the residue classes of the terms in O are a K-vector space basis of P/I. Below se shall see that, given an O-border prebasis G, the set O is always a system of generators of the K-vector space P/ G. i=1 7-b
29 Example of a Border Basis Example 2.3 Consider the oder ideal O = {1, x, y, xy} in T 2. Its border is O = {x 2, x 2 y, xy 2, y 2 }. 8
30 Example of a Border Basis Example 2.3 Consider the oder ideal O = {1, x, y, xy} in T 2. Its border is O = {x 2, x 2 y, xy 2, y 2 }. y x 8-a
31 Example of a Border Basis Example 2.3 Consider the oder ideal O = {1, x, y, xy} in T 2. Its border is O = {x 2, x 2 y, xy 2, y 2 }. y The set of polynomials G = {g 1, g 2, g 3, g 4 } where g 1 = x 2 x, g 2 = x 2 y xy, g 3 = xy 2 xy, g 4 = y 2 y is an O-border basis of I. x 8-b
32 3 Properties of GB and BB Martin s Limerick: 9
33 3 Properties of GB and BB Martin s Limerick: The list of the theorems I knew made limericks end at line two. 9-a
34 3 Properties of GB and BB Martin s Limerick: The list of the theorems I knew made limericks end at line two. Proposition 3.1 (Existence and Uniqueness of GB) (a) For every term ordering σ and every ideal I P, there exists a σ-gröbner basis of I. 9-b
35 3 Properties of GB and BB Martin s Limerick: The list of the theorems I knew made limericks end at line two. Proposition 3.1 (Existence and Uniqueness of GB) (a) For every term ordering σ and every ideal I P, there exists a σ-gröbner basis of I. (b) A σ-gröbner basis of I is a system of generators of I. 9-c
36 3 Properties of GB and BB Martin s Limerick: The list of the theorems I knew made limericks end at line two. Proposition 3.1 (Existence and Uniqueness of GB) (a) For every term ordering σ and every ideal I P, there exists a σ-gröbner basis of I. (b) A σ-gröbner basis of I is a system of generators of I. (c) For every term ordering σ, an ideal I P has a unique reduced σ-gröbner basis, i.e. a GB which is minimal, monic, and completely interreduced. 9-d
37 For border bases, we shall always use the following notation. 10
38 For border bases, we shall always use the following notation. O = {t 1,...,t µ } order ideal with border O = {b 1,...,b ν } G = {g 1,...,g ν } is an O-border prebasis, where g j = b j µ i=1 c ij t i with c ij K 10-a
39 For border bases, we shall always use the following notation. O = {t 1,...,t µ } order ideal with border O = {b 1,...,b ν } G = {g 1,...,g ν } is an O-border prebasis, where g j = b j µ i=1 c ij t i with c ij K Proposition 3.2 (Existence and Uniqueness of BB) (a) Given an order ideal O, a 0-dimensional polynomial ideal I need not have an O-border basis, even if #O = dim K (P/I). 10-b
40 For border bases, we shall always use the following notation. O = {t 1,...,t µ } order ideal with border O = {b 1,...,b ν } G = {g 1,...,g ν } is an O-border prebasis, where g j = b j µ i=1 c ij t i with c ij K Proposition 3.2 (Existence and Uniqueness of BB) (a) Given an order ideal O, a 0-dimensional polynomial ideal I need not have an O-border basis, even if #O = dim K (P/I). (b) If a 0-dimensional ideal I P has an O-border basis G then G generates I. 10-c
41 For border bases, we shall always use the following notation. O = {t 1,...,t µ } order ideal with border O = {b 1,...,b ν } G = {g 1,...,g ν } is an O-border prebasis, where g j = b j µ i=1 c ij t i with c ij K Proposition 3.2 (Existence and Uniqueness of BB) (a) Given an order ideal O, a 0-dimensional polynomial ideal I need not have an O-border basis, even if #O = dim K (P/I). (b) If a 0-dimensional ideal I P has an O-border basis G then G generates I. (c) If a 0-dimensional ideal I P has an O-border basis G then G is uniquely determined. 10-d
42 The Relation Between GB and BB Let σ be a term ordering. Then O σ (I) = T n \ LT σ (I) is an order ideal of terms. By Macaulay s Basis Theorem, the residue classes of O σ (I) form a K-basis of P/I. 11
43 The Relation Between GB and BB Let σ be a term ordering. Then O σ (I) = T n \ LT σ (I) is an order ideal of terms. By Macaulay s Basis Theorem, the residue classes of O σ (I) form a K-basis of P/I. Proposition 3.3 (Border Bases Generalize Gröbner Bases) If O is of the form T n \ LT σ (I) for some term ordering σ, then I has an O-border basis. It contains the reduced σ-gröbner basis of I. The elements of the reduced σ-gb are exactly the border basis polynomials corresponding to the corners of O, i.e. to the minimal generators of the border term ideal. 11-a
44 4 Division Algorithms What is a proof? 12
45 4 Division Algorithms What is a proof? One half percent of alcohol. 12-a
46 4 Division Algorithms What is a proof? One half percent of alcohol. Theorem 4.1 (The Division Algorithm) Let σ be a term ordering, f P, and G = (g 1,...,g ν ) P ν. Consider the following instructions: D1. Let q 1 = = q ν = 0, p = 0, and v = f. D2. Find the smallest i {1,...,ν} such that LT σ (v) is a multiple of LT σ (g i ). If such an i exists, replace q i by q i + LM σ(v) LM σ (g i ) and v by v LM σ(v) LM σ (g i ) g i. 12-b
47 D3. Repeat step D2 until there is no more i {1,...,ν} such that LT σ (v) is a multiple of LT σ (g i ). Then replace p by p + LM σ (v) and v by v LM σ (v). D4. If now v 0, start again with step D2. If v = 0, return the tuple (q 1,...,q ν ) P ν and p P. 13
48 D3. Repeat step D2 until there is no more i {1,...,ν} such that LT σ (v) is a multiple of LT σ (g i ). Then replace p by p + LM σ (v) and v by v LM σ (v). D4. If now v 0, start again with step D2. If v = 0, return the tuple (q 1,...,q ν ) P ν and p P. This is an algorithm which returns a tuple (q 1,...,q ν ) P ν and p P such that f = q 1 g q ν g ν + p such that Supp(p) LT σ (g 1 ),...,LT σ (g ν ) =, and such that LT σ (q i g i ) σ LT σ (m) if q i a
49 D3. Repeat step D2 until there is no more i {1,...,ν} such that LT σ (v) is a multiple of LT σ (g i ). Then replace p by p + LM σ (v) and v by v LM σ (v). D4. If now v 0, start again with step D2. If v = 0, return the tuple (q 1,...,q ν ) P ν and p P. This is an algorithm which returns a tuple (q 1,...,q ν ) P ν and p P such that f = q 1 g q ν g ν + p such that Supp(p) LT σ (g 1 ),...,LT σ (g ν ) =, and such that LT σ (q i g i ) σ LT σ (m) if q i 0. Definition 4.2 The element NR σ,g (f) = p is called the normal remainder of f with respect to division by G. 13-b
50 Definition 4.3 Let O 0 = O and O i = O i 1 O i 1 for i 1. For every term t T n, there is then a unique number i = ind O (t) 0 such that t O i \ O i 1. It is called the O-index of t. Theorem 4.4 (The Border Division Algorithm) Given a polynomial f, consider the following steps: B1. Let f 1 = = f ν = 0, c 1 = = c µ = 0, and h = f. B2. If h = 0, then return (f 1,...,f ν, c 1,...,c µ ) and stop. B3. If ind O (h) = 0, then find c 1,...,c µ K such that h = c 1 t c µ t µ. Return (f 1,...,f ν, c 1,...,c µ ) and stop. 14
51 B4. If ind O (h) > 0, then let h = a 1 h a s h s with a 1,...,a s K \ {0} and h 1,...,h s T n such that ind O (h 1 ) = ind O (h). Determine the smallest index i {1,...,ν} such that h 1 factors as h 1 = t b i with a term t of degree ind O (h) 1. Subtract a 1 t g i from h, add a 1 t to f i, and continue with step B2. 15
52 B4. If ind O (h) > 0, then let h = a 1 h a s h s with a 1,...,a s K \ {0} and h 1,...,h s T n such that ind O (h 1 ) = ind O (h). Determine the smallest index i {1,...,ν} such that h 1 factors as h 1 = t b i with a term t of degree ind O (h) 1. Subtract a 1 t g i from h, add a 1 t to f i, and continue with step B2. This is an algorithm that returns a tuple (f 1,...,f ν, c 1,...,c µ ) P ν K µ such that f = f 1 g f ν g ν + c 1 t c µ t µ and deg(f i ) ind O (f) 1 for all i {1,...,ν} with f i g i a
53 B4. If ind O (h) > 0, then let h = a 1 h a s h s with a 1,...,a s K \ {0} and h 1,...,h s T n such that ind O (h 1 ) = ind O (h). Determine the smallest index i {1,...,ν} such that h 1 factors as h 1 = t b i with a term t of degree ind O (h) 1. Subtract a 1 t g i from h, add a 1 t to f i, and continue with step B2. This is an algorithm that returns a tuple (f 1,...,f ν, c 1,...,c µ ) P ν K µ such that f = f 1 g f ν g ν + c 1 t c µ t µ and deg(f i ) ind O (f) 1 for all i {1,...,ν} with f i g i 0. Corollary 4.5 The residue classes of the elements of O generate the K-vector space P/I. 15-b
54 Gröbner Bases and Rewriting Systems Let σ be a term ordering on T n and G = {g 1,...,g ν } (P \ {0}) ν. 16
55 Gröbner Bases and Rewriting Systems Let σ be a term ordering on T n and G = {g 1,...,g ν } (P \ {0}) ν. Definition 4.6 (a) Let f 1, f 2 P, and suppose there exist a constant c K, a term t T n, and an index i {1,...,ν} such that f 2 = f 1 c tg i and t LT σ (g i ) / Supp(f 2 ). Then we say that f 1 reduces to f 2 in one step, and we write f 1 g i f2. 16-a
56 Gröbner Bases and Rewriting Systems Let σ be a term ordering on T n and G = {g 1,...,g ν } (P \ {0}) ν. Definition 4.6 (a) Let f 1, f 2 P, and suppose there exist a constant c K, a term t T n, and an index i {1,...,ν} such that f 2 = f 1 c tg i and t LT σ (g i ) / Supp(f 2 ). Then we say that f 1 reduces to f 2 in one step, and we write f 1 g i f2. (b) The transitive closure of the relations g 1 g s,..., is called the rewrite relation defined by G and is denoted by. G 16-b
57 Gröbner Bases and Rewriting Systems Let σ be a term ordering on T n and G = {g 1,...,g ν } (P \ {0}) ν. Definition 4.6 (a) Let f 1, f 2 P, and suppose there exist a constant c K, a term t T n, and an index i {1,...,ν} such that f 2 = f 1 c tg i and t LT σ (g i ) / Supp(f 2 ). Then we say that f 1 reduces to f 2 in one step, and we write f 1 g i f2. (b) The transitive closure of the relations g 1 g s,..., is called the rewrite relation defined by G and is denoted by. G Proposition 4.7 A set of polynomials G = {g 1,...,g ν } is a σ-gröbner basis if and only if the rewrite rule G is confluent. This means that if there are reductions f 1 G f2 and f 1 G f3 then there exist a polynomial f 4 and reductions f 2 G f4 and f 3 G f4. 16-c
58 Border Bases and Rewriting Systems Proposition 4.8 Let G = {g 1,...,g ν } be an O-border prebasis. Then G is an O-border basis if and only if the rewriting system defined by the rules b j µ c ij t i is confluent. i=1 17
59 Border Bases and Rewriting Systems Proposition 4.8 Let G = {g 1,...,g ν } be an O-border prebasis. Then G is an O-border basis if and only if the rewriting system defined by the rules b j µ c ij t i is confluent. i=1 Notice that this rewriting system is in general not terminating, i.e. not Noetherian. This means that there may be an infinite sequences of reductions f 1 G f2 G f3 G 17-a
60 5 Neighbors Give a man a fish and he will eat for a day. Teach him how to fish, and he will 18
61 5 Neighbors Give a man a fish and he will eat for a day. Teach him how to fish, and he will sit in a boat and drink beer all day. 18-a
62 5 Neighbors Give a man a fish and he will eat for a day. Teach him how to fish, and he will sit in a boat and drink beer all day. Definition 5.1 Let b i, b j O be two distinct border terms. 18-b
63 5 Neighbors Give a man a fish and he will eat for a day. Teach him how to fish, and he will sit in a boat and drink beer all day. Definition 5.1 Let b i, b j O be two distinct border terms. (a) The border terms b i and b j are called next-door neighbors if b i = x k b j for some k {1,...,n}. 18-c
64 5 Neighbors Give a man a fish and he will eat for a day. Teach him how to fish, and he will sit in a boat and drink beer all day. Definition 5.1 Let b i, b j O be two distinct border terms. (a) The border terms b i and b j are called next-door neighbors if b i = x k b j for some k {1,...,n}. (b) The border terms b i and b j are called across-the-street neighbors if x k b i = x l b j for some k, l {1,...,n}. 18-d
65 5 Neighbors Give a man a fish and he will eat for a day. Teach him how to fish, and he will sit in a boat and drink beer all day. Definition 5.1 Let b i, b j O be two distinct border terms. (a) The border terms b i and b j are called next-door neighbors if b i = x k b j for some k {1,...,n}. (b) The border terms b i and b j are called across-the-street neighbors if x k b i = x l b j for some k, l {1,...,n}. (c) The border terms b i and b j are called neighbors if they are next-door neighbors or across-the-street neighbors. 18-e
66 Example 5.2 The border of O = {1, x, y, xy} is O = {x 2, x 2 y, xy 2, y 2 }. Here the neighbor relations look as follows: (x 2, x 2 y) and (y 2, xy 2 ) are next-door neighbor pairs (x 2 y, xy 2 ) is an across-the-street neighbor pair y x 19
67 Neighbor Syzygies Definition 5.3 (a) For t, t T n, we call the pair (lcm(t, t )/t, lcm(t, t )/t ) the fundamental syzygy of (t, t ). 20
68 Neighbor Syzygies Definition 5.3 (a) For t, t T n, we call the pair (lcm(t, t )/t, lcm(t, t )/t ) the fundamental syzygy of (t, t ). (b) The fundamental syzygies of neighboring border terms are also called the neighbor syzygies. 20-a
69 Neighbor Syzygies Definition 5.3 (a) For t, t T n, we call the pair (lcm(t, t )/t, lcm(t, t )/t ) the fundamental syzygy of (t, t ). (b) The fundamental syzygies of neighboring border terms are also called the neighbor syzygies. Proposition 5.4 (a) Given a tuple of terms (t 1,...,t r ), the fundamental syzygies σ ij = (lcm(t i, t j )/t i ) e i (lcm(t i, t j )/t j ) e j such that 1 i < j r generate the syzygy module Syz P (t 1,...,t r ) = {(f 1,...,f r ) P r f 1 t f r t r = 0}. 20-b
70 Neighbor Syzygies Definition 5.3 (a) For t, t T n, we call the pair (lcm(t, t )/t, lcm(t, t )/t ) the fundamental syzygy of (t, t ). (b) The fundamental syzygies of neighboring border terms are also called the neighbor syzygies. Proposition 5.4 (a) Given a tuple of terms (t 1,...,t r ), the fundamental syzygies σ ij = (lcm(t i, t j )/t i ) e i (lcm(t i, t j )/t j ) e j such that 1 i < j r generate the syzygy module Syz P (t 1,...,t r ) = {(f 1,...,f r ) P r f 1 t f r t r = 0}. (b) The neighbor syzygies generate the module of border syzygies Syz P (b 1,...,b ν ). 20-c
71 6 The Buchberger Criterion What is higher mathematics? 21
72 6 The Buchberger Criterion What is higher mathematics? If you awake in the morning with an unknown. 21-a
73 6 The Buchberger Criterion What is higher mathematics? If you awake in the morning with an unknown. Definition 6.1 Let g i, g j G be two distinct border prebasis polynomials. Then the polynomial S ij = (lcm(b i, b j )/b i ) g i (lcm(b i, b j )/b j ) g j is called the S-polynomial of g i and g j. 21-b
74 6 The Buchberger Criterion What is higher mathematics? If you awake in the morning with an unknown. Definition 6.1 Let g i, g j G be two distinct border prebasis polynomials. Then the polynomial S ij = (lcm(b i, b j )/b i ) g i (lcm(b i, b j )/b j ) g j is called the S-polynomial of g i and g j. Theorem 6.2 (Stetter) An O-border prebasis G is an O-border basis if and only if the neighbor syzygies lift, i.e. if and only if we have NR O,G (S ij ) = 0 for all (i, j) such that (b i, b j ) is a pair of neighbors. 21-c
75 Advantages of Border Bases 22
76 Advantages of Border Bases 1. Border bases are numerically stable. If one changes the coefficicients of some polynomials generating I slightly, the border basis of I changes continuously. 22-a
77 Advantages of Border Bases 1. Border bases are numerically stable. If one changes the coefficicients of some polynomials generating I slightly, the border basis of I changes continuously. 2. Border bases preserve symmetries. There are many more order ideals O for which a given ideal I has a border basis than order ideals of the form O σ (I) = T n \ LT σ (I). Frequently, there are border bases having the same symmetries as the initial generating system. 22-b
78 Advantages of Border Bases 1. Border bases are numerically stable. If one changes the coefficicients of some polynomials generating I slightly, the border basis of I changes continuously. 2. Border bases preserve symmetries. There are many more order ideals O for which a given ideal I has a border basis than order ideals of the form O σ (I) = T n \ LT σ (I). Frequently, there are border bases having the same symmetries as the initial generating system. 3. Border bases yield an explicit moduli space. The cefficients of a border prebasis are parametrized by an affine space. The border basis scheme is defined in this affine space by explicit equations. 22-c
Lecture 5: Ideals of Points
Lecture 5: Ideals of Points The Vanishing Lecture Martin Kreuzer Fakultät für Informatik und Mathematik Universität Passau martin.kreuzer@ uni-passau.de Sophus Lie Center Nordfjordeid June 18, 2009 1 Contents
More informationAlgebraic Oil. Martin Kreuzer Fakultät für Informatik und Mathematik Universität Passau uni-passau.de. NOCAS Passau December 10, 2008
Algebraic Oil Martin Kreuzer Fakultät für Informatik und Mathematik Universität Passau martin.kreuzer@ uni-passau.de NOCAS Passau December 10, 2008 1 Contents 1. Some Problems in Oil Production 2. Border
More informationFrom Oil Fields to Hilbert Schemes
Chapter 1 From Oil Fields to Hilbert Schemes Martin Kreuzer, Hennie Poulisse, and Lorenzo Robbiano Abstract New techniques for dealing with problems of numerical stability in computations involving multivariate
More informationOil Fields and Hilbert Schemes
Oil Fields and Hilbert Schemes Lorenzo Robbiano Università di Genova Dipartimento di Matematica Lorenzo Robbiano (Università di Genova) Oil Fields and Hilbert Schemes March, 2008 1 / 35 Facts In the realm
More informationLecture 1. (i,j) N 2 kx i y j, and this makes k[x, y]
Lecture 1 1. Polynomial Rings, Gröbner Bases Definition 1.1. Let R be a ring, G an abelian semigroup, and R = i G R i a direct sum decomposition of abelian groups. R is graded (G-graded) if R i R j R i+j
More informationAn algebraist s view on border bases
4 An algebraist s view on border bases Achim Kehrein 1, Martin Kreuzer 1, and Lorenzo Robbiano 2 1 Universität Dortmund, Fachbereich Mathematik, 44221 Dortmund, Germany, achim.kehrein@mathematik.uni-dortmund.de
More informationMath 4370 Exam 1. Handed out March 9th 2010 Due March 18th 2010
Math 4370 Exam 1 Handed out March 9th 2010 Due March 18th 2010 Problem 1. Recall from problem 1.4.6.e in the book, that a generating set {f 1,..., f s } of I is minimal if I is not the ideal generated
More informationPOLYNOMIAL DIVISION AND GRÖBNER BASES. Samira Zeada
THE TEACHING OF MATHEMATICS 2013, Vol. XVI, 1, pp. 22 28 POLYNOMIAL DIVISION AND GRÖBNER BASES Samira Zeada Abstract. Division in the ring of multivariate polynomials is usually not a part of the standard
More informationM3P23, M4P23, M5P23: COMPUTATIONAL ALGEBRA & GEOMETRY REVISION SOLUTIONS
M3P23, M4P23, M5P23: COMPUTATIONAL ALGEBRA & GEOMETRY REVISION SOLUTIONS (1) (a) Fix a monomial order. A finite subset G = {g 1,..., g m } of an ideal I k[x 1,..., x n ] is called a Gröbner basis if (LT(g
More informationLecture 2: Gröbner Basis and SAGBI Basis
Lecture 2: Gröbner Basis and SAGBI Basis Mohammed Tessema Suppose we have a graph. Suppose we color the graph s vertices with 3 colors so that if the vertices are adjacent they are not the same colors.
More informationGroebner Bases and Applications
Groebner Bases and Applications Robert Hines December 16, 2014 1 Groebner Bases In this section we define Groebner Bases and discuss some of their basic properties, following the exposition in chapter
More informationToric ideals finitely generated up to symmetry
Toric ideals finitely generated up to symmetry Anton Leykin Georgia Tech MOCCA, Levico Terme, September 2014 based on [arxiv:1306.0828] Noetherianity for infinite-dimensional toric varieties (with Jan
More informationComputing the Bernstein-Sato polynomial
Computing the Bernstein-Sato polynomial Daniel Andres Kaiserslautern 14.10.2009 Daniel Andres (RWTH Aachen) Computing the Bernstein-Sato polynomial Kaiserslautern 2009 1 / 21 Overview 1 Introduction 2
More informationGröbner Bases. eliminating the leading term Buchberger s criterion and algorithm. construct wavelet filters
Gröbner Bases 1 S-polynomials eliminating the leading term Buchberger s criterion and algorithm 2 Wavelet Design construct wavelet filters 3 Proof of the Buchberger Criterion two lemmas proof of the Buchberger
More informationThe F 4 Algorithm. Dylan Peifer. 9 May Cornell University
The F 4 Algorithm Dylan Peifer Cornell University 9 May 2017 Gröbner Bases History Gröbner bases were introduced in 1965 in the PhD thesis of Bruno Buchberger under Wolfgang Gröbner. Buchberger s algorithm
More informationHilbert Polynomials. dimension and counting monomials. a Gröbner basis for I reduces to in > (I)
Hilbert Polynomials 1 Monomial Ideals dimension and counting monomials 2 The Dimension of a Variety a Gröbner basis for I reduces to in > (I) 3 The Complexity of Gröbner Bases a bound on the degrees of
More informationGroebner Bases, Toric Ideals and Integer Programming: An Application to Economics. Tan Tran Junior Major-Economics& Mathematics
Groebner Bases, Toric Ideals and Integer Programming: An Application to Economics Tan Tran Junior Major-Economics& Mathematics History Groebner bases were developed by Buchberger in 1965, who later named
More informationWORKING WITH MULTIVARIATE POLYNOMIALS IN MAPLE
WORKING WITH MULTIVARIATE POLYNOMIALS IN MAPLE JEFFREY B. FARR AND ROMAN PEARCE Abstract. We comment on the implementation of various algorithms in multivariate polynomial theory. Specifically, we describe
More informationNon-commutative reduction rings
Revista Colombiana de Matemáticas Volumen 33 (1999), páginas 27 49 Non-commutative reduction rings Klaus Madlener Birgit Reinert 1 Universität Kaiserslautern, Germany Abstract. Reduction relations are
More informationSets of Points and Mathematical Models
Sets of Points and Mathematical Models Lorenzo Robbiano Università di Genova Dipartimento di Matematica Lorenzo Robbiano (Università di Genova) Points and Models Osnabrück, June 2013 1 / 79 Standard References
More informationLecture 4 February 5
Math 239: Discrete Mathematics for the Life Sciences Spring 2008 Lecture 4 February 5 Lecturer: Lior Pachter Scribe/ Editor: Michaeel Kazi/ Cynthia Vinzant 4.1 Introduction to Gröbner Bases In this lecture
More informationReversely Well-Ordered Valuations on Polynomial Rings in Two Variables
Reversely Well-Ordered Valuations on Polynomial Rings in Two Variables Edward Mosteig Loyola Marymount University Los Angeles, California, USA Workshop on Valuations on Rational Function Fields Department
More informationOn the minimal free resolution of a monomial ideal.
On the minimal free resolution of a monomial ideal. Caitlin M c Auley August 2012 Abstract Given a monomial ideal I in the polynomial ring S = k[x 1,..., x n ] over a field k, we construct a minimal free
More informationPolynomials, Ideals, and Gröbner Bases
Polynomials, Ideals, and Gröbner Bases Notes by Bernd Sturmfels for the lecture on April 10, 2018, in the IMPRS Ringvorlesung Introduction to Nonlinear Algebra We fix a field K. Some examples of fields
More informationNew Strategies for Computing Gröbner Bases
New Strategies for Computing Gröbner Bases Bruno Simões Department of Mathematics University Trento Advisor: Prof. Lorenzo Robbiano University of Genova A thesis submitted for the degree of PhilosophiæDoctor
More informationAbstract Algebra for Polynomial Operations. Maya Mohsin Ahmed
Abstract Algebra for Polynomial Operations Maya Mohsin Ahmed c Maya Mohsin Ahmed 2009 ALL RIGHTS RESERVED To my students As we express our gratitude, we must never forget that the highest appreciation
More information5 The existence of Gröbner basis
5 The existence of Gröbner basis We use Buchberger s criterion from the previous section to give an algorithm that constructs a Gröbner basis of an ideal from any given set of generators Hilbert s Basis
More informationA gentle introduction to Elimination Theory. March METU. Zafeirakis Zafeirakopoulos
A gentle introduction to Elimination Theory March 2018 @ METU Zafeirakis Zafeirakopoulos Disclaimer Elimination theory is a very wide area of research. Z.Zafeirakopoulos 2 Disclaimer Elimination theory
More informationLECTURE 4: GOING-DOWN THEOREM AND NORMAL RINGS
LECTURE 4: GOING-DOWN THEOREM AND NORMAL RINGS Definition 0.1. Let R be a domain. We say that R is normal (integrally closed) if R equals the integral closure in its fraction field Q(R). Proposition 0.2.
More informationIDEALS AND THEIR INTEGRAL CLOSURE
IDEALS AND THEIR INTEGRAL CLOSURE ALBERTO CORSO (joint work with C. Huneke and W.V. Vasconcelos) Department of Mathematics Purdue University West Lafayette, 47907 San Diego January 8, 1997 1 SETTING Let
More informationNotes 6: Polynomials in One Variable
Notes 6: Polynomials in One Variable Definition. Let f(x) = b 0 x n + b x n + + b n be a polynomial of degree n, so b 0 0. The leading term of f is LT (f) = b 0 x n. We begin by analyzing the long division
More informationComputing syzygies with Gröbner bases
Computing syzygies with Gröbner bases Steven V Sam July 2, 2008 1 Motivation. The aim of this article is to motivate the inclusion of Gröbner bases in algebraic geometry via the computation of syzygies.
More informationCurrent Advances. Open Source Gröbner Basis Algorithms
Current Advances in Open Source Gröbner Basis Algorithms My name is Christian Eder I am from the University of Kaiserslautern 3 years ago Christian Eder, Jean-Charles Faugère A survey on signature-based
More informationLetterplace ideals and non-commutative Gröbner bases
Letterplace ideals and non-commutative Gröbner bases Viktor Levandovskyy and Roberto La Scala (Bari) RWTH Aachen 13.7.09, NOCAS, Passau, Niederbayern La Scala, Levandovskyy (RWTH) Letterplace ideals 13.7.09
More informationOn the BMS Algorithm
On the BMS Algorithm Shojiro Sakata The University of Electro-Communications Department of Information and Communication Engineering Chofu-shi, Tokyo 182-8585, JAPAN Abstract I will present a sketch of
More informationMCS 563 Spring 2014 Analytic Symbolic Computation Monday 27 January. Gröbner bases
Gröbner bases In this lecture we introduce Buchberger s algorithm to compute a Gröbner basis for an ideal, following [2]. We sketch an application in filter design. Showing the termination of Buchberger
More informationGröbner bases for the polynomial ring with infinite variables and their applications
Gröbner bases for the polynomial ring with infinite variables and their applications Kei-ichiro Iima and Yuji Yoshino Abstract We develop the theory of Gröbner bases for ideals in a polynomial ring with
More informationProblem Set 1 Solutions
Math 918 The Power of Monomial Ideals Problem Set 1 Solutions Due: Tuesday, February 16 (1) Let S = k[x 1,..., x n ] where k is a field. Fix a monomial order > σ on Z n 0. (a) Show that multideg(fg) =
More informationLecture 15: Algebraic Geometry II
6.859/15.083 Integer Programming and Combinatorial Optimization Fall 009 Today... Ideals in k[x] Properties of Gröbner bases Buchberger s algorithm Elimination theory The Weak Nullstellensatz 0/1-Integer
More informationFrom Gauss. to Gröbner Bases. John Perry. The University of Southern Mississippi. From Gauss to Gröbner Bases p.
From Gauss to Gröbner Bases p. From Gauss to Gröbner Bases John Perry The University of Southern Mississippi From Gauss to Gröbner Bases p. Overview Questions: Common zeroes? Tool: Gaussian elimination
More informationPage 23, part (c) of Exercise 5: Adapt the argument given at the end of the section should be Adapt the argument used for the circle x 2 +y 2 = 1
Ideals, Varieties and Algorithms, fourth edition Errata for the fourth edition as of August 6, 2018 Page 23, part (c) of Exercise 5: Adapt the argument given at the end of the section should be Adapt the
More informationMath 615: Lecture of January 10, 2007
Math 615: Lecture of January 10, 2007 The definition of lexicographic order is quite simple, but the totally ordered set that one gets is not even if there are only two variables one has 1 < x 2 < x 2
More informationMINIMAL GENERATING SETS OF GROUPS, RINGS, AND FIELDS
MINIMAL GENERATING SETS OF GROUPS, RINGS, AND FIELDS LORENZ HALBEISEN, MARTIN HAMILTON, AND PAVEL RŮŽIČKA Abstract. A subset X of a group (or a ring, or a field) is called generating, if the smallest subgroup
More informationDedekind Domains. Mathematics 601
Dedekind Domains Mathematics 601 In this note we prove several facts about Dedekind domains that we will use in the course of proving the Riemann-Roch theorem. The main theorem shows that if K/F is a finite
More informationSlimgb. Gröbner bases with slim polynomials
Slimgb Gröbner bases with slim polynomials The Aim avoid intermediate expression swell Classical Buchberger algorithm with parallel reductions guided by new weighted length functions Often: big computations
More informationHilbert function, Betti numbers. Daniel Gromada
Hilbert function, Betti numbers 1 Daniel Gromada References 2 David Eisenbud: Commutative Algebra with a View Toward Algebraic Geometry 19, 110 David Eisenbud: The Geometry of Syzygies 1A, 1B My own notes
More informationBounding the number of affine roots
with applications in reliable and secure communication Inaugural Lecture, Aalborg University, August 11110, 11111100000 with applications in reliable and secure communication Polynomials: F (X ) = 2X 2
More information1 Absolute values and discrete valuations
18.785 Number theory I Lecture #1 Fall 2015 09/10/2015 1 Absolute values and discrete valuations 1.1 Introduction At its core, number theory is the study of the ring Z and its fraction field Q. Many questions
More informationDe Nugis Groebnerialium 5: Noether, Macaulay, Jordan
De Nugis Groebnerialium 5: Noether, Macaulay, Jordan ACA 2018 Santiago de Compostela Re-reading Macaulay References Macaulay F. S., On the Resolution of a given Modular System into Primary Systems including
More informationGRÖBNER BASES AND POLYNOMIAL EQUATIONS. 1. Introduction and preliminaries on Gróbner bases
GRÖBNER BASES AND POLYNOMIAL EQUATIONS J. K. VERMA 1. Introduction and preliminaries on Gróbner bases Let S = k[x 1, x 2,..., x n ] denote a polynomial ring over a field k where x 1, x 2,..., x n are indeterminates.
More informationSummer Project. August 10, 2001
Summer Project Bhavana Nancherla David Drescher August 10, 2001 Over the summer we embarked on a brief introduction to various concepts in algebraic geometry. We used the text Ideals, Varieties, and Algorithms,
More information2. Intersection Multiplicities
2. Intersection Multiplicities 11 2. Intersection Multiplicities Let us start our study of curves by introducing the concept of intersection multiplicity, which will be central throughout these notes.
More informationON THE CONNECTION OF THE SHERALI-ADAMS CLOSURE AND BORDER BASES
ON THE CONNECTION OF THE SHERALI-ADAMS CLOSURE AND BORDER BASES SEBASTIAN POKUTTA AND ANDREAS S. SCHULZ ABSTRACT. The Sherali-Adams lift-and-project hierarchy is a fundamental construct in integer programming,
More informationSmooth morphisms. Peter Bruin 21 February 2007
Smooth morphisms Peter Bruin 21 February 2007 Introduction The goal of this talk is to define smooth morphisms of schemes, which are one of the main ingredients in Néron s fundamental theorem [BLR, 1.3,
More informationRECURSIVE RELATIONS FOR THE HILBERT SERIES FOR CERTAIN QUADRATIC IDEALS. 1. Introduction
RECURSIVE RELATIONS FOR THE HILBERT SERIES FOR CERTAIN QUADRATIC IDEALS 1 RECURSIVE RELATIONS FOR THE HILBERT SERIES FOR CERTAIN QUADRATIC IDEALS AUTHOR: YUZHE BAI SUPERVISOR: DR. EUGENE GORSKY Abstract.
More informationRota-Baxter Type Operators, Rewriting Systems, and Gröbner-Shirshov Bases, Part II
Rota-Baxter Type Operators, Rewriting Systems, and Gröbner-Shirshov Bases, Part II William Sit 1 The City College of The City University of New York Kolchin Seminar in Differential Algebra December 9,
More information4 Hilbert s Basis Theorem and Gröbner basis
4 Hilbert s Basis Theorem and Gröbner basis We define Gröbner bases of ideals in multivariate polynomial rings and see how they work in tandem with the division algorithm. We look again at the standard
More informationIntroduction to Gröbner Bases for Geometric Modeling. Geometric & Solid Modeling 1989 Christoph M. Hoffmann
Introduction to Gröbner Bases for Geometric Modeling Geometric & Solid Modeling 1989 Christoph M. Hoffmann Algebraic Geometry Branch of mathematics. Express geometric facts in algebraic terms in order
More informationOn Conversions from CNF to ANF
On Conversions from CNF to ANF Jan Horáček Martin Kreuzer Faculty of Informatics and Mathematics University of Passau, Germany Jan.Horacek@uni-passau.de Martin.Kreuzer@uni-passau.de Background ANF is XOR
More informationNUMERICAL MONOIDS (I)
Seminar Series in Mathematics: Algebra 2003, 1 8 NUMERICAL MONOIDS (I) Introduction The numerical monoids are simple to define and naturally appear in various parts of mathematics, e.g. as the values monoids
More informationMath 40510, Algebraic Geometry
Math 40510, Algebraic Geometry Problem Set 1, due February 10, 2016 1. Let k = Z p, the field with p elements, where p is a prime. Find a polynomial f k[x, y] that vanishes at every point of k 2. [Hint:
More informationTHE DEFICIENCY MODULE OF A CURVE AND ITS SUBMODULES
THE DEFICIENCY MODULE OF A CURVE AND ITS SUBMODULES GUNTRAM HAINKE AND ALMAR KAID 1. Introduction This is a summary of the fifth tutorial handed out at the CoCoA summer school 2005. We discuss the so-called
More informationPrimary Decomposition
Primary Decomposition p. Primary Decomposition Gerhard Pfister pfister@mathematik.uni-kl.de Departement of Mathematics University of Kaiserslautern Primary Decomposition p. Primary Decomposition:References
More informationStandard Bases for Linear Codes over Prime Fields
Standard Bases for Linear Codes over Prime Fields arxiv:1708.05490v1 cs.it] 18 Aug 2017 Jean Jacques Ferdinand RANDRIAMIARAMPANAHY 1 e-mail : randriamiferdinand@gmail.com Harinaivo ANDRIATAHINY 2 e-mail
More informationJournal of Algebra 226, (2000) doi: /jabr , available online at on. Artin Level Modules.
Journal of Algebra 226, 361 374 (2000) doi:10.1006/jabr.1999.8185, available online at http://www.idealibrary.com on Artin Level Modules Mats Boij Department of Mathematics, KTH, S 100 44 Stockholm, Sweden
More informationCoding Theory: A Gröbner Basis Approach
Eindhoven University of Technology Department of Mathematics and Computer Science Coding Theory: A Gröbner Basis Approach Master s Thesis by D.W.C. Kuijsters Supervised by Dr. G.R. Pellikaan February 6,
More informationCOURSE SUMMARY FOR MATH 508, WINTER QUARTER 2017: ADVANCED COMMUTATIVE ALGEBRA
COURSE SUMMARY FOR MATH 508, WINTER QUARTER 2017: ADVANCED COMMUTATIVE ALGEBRA JAROD ALPER WEEK 1, JAN 4, 6: DIMENSION Lecture 1: Introduction to dimension. Define Krull dimension of a ring A. Discuss
More informationTHE BUCHBERGER RESOLUTION ANDA OLTEANU AND VOLKMAR WELKER
THE BUCHBERGER RESOLUTION ANDA OLTEANU AND VOLKMAR WELKER arxiv:1409.2041v2 [math.ac] 11 Sep 2014 Abstract. We define the Buchberger resolution, which is a graded free resolution of a monomial ideal in
More informationOn Vector Product Algebras
On Vector Product Algebras By Markus Rost. This text contains some remarks on vector product algebras and the graphical techniques. It is partially contained in the diploma thesis of D. Boos and S. Maurer.
More informationNUMERICAL MACAULIFICATION
NUMERICAL MACAULIFICATION JUAN MIGLIORE AND UWE NAGEL Abstract. An unpublished example due to Joe Harris from 1983 (or earlier) gave two smooth space curves with the same Hilbert function, but one of the
More informationMCS 563 Spring 2014 Analytic Symbolic Computation Friday 31 January. Quotient Rings
Quotient Rings In this note we consider again ideals, but here we do not start from polynomials, but from a finite set of points. The application in statistics and the pseudo code of the Buchberger-Möller
More informationUnderstanding and Implementing F5
Understanding and Implementing F5 John Perry john.perry@usm.edu University of Southern Mississippi Understanding and Implementing F5 p.1 Overview Understanding F5 Description Criteria Proofs Implementing
More informationFILTERED RINGS AND MODULES. GRADINGS AND COMPLETIONS.
FILTERED RINGS AND MODULES. GRADINGS AND COMPLETIONS. Let A be a ring, for simplicity assumed commutative. A filtering, or filtration, of an A module M means a descending sequence of submodules M = M 0
More informationTHROUGH THE FIELDS AND FAR AWAY
THROUGH THE FIELDS AND FAR AWAY JONATHAN TAYLOR I d like to thank Prof. Stephen Donkin for helping me come up with the topic of my project and also guiding me through its various complications. Contents
More informationON CERTAIN CLASSES OF CURVE SINGULARITIES WITH REDUCED TANGENT CONE
ON CERTAIN CLASSES OF CURVE SINGULARITIES WITH REDUCED TANGENT CONE Alessandro De Paris Università degli studi di Napoli Federico II Dipartimento di Matematica e Applicazioni R. Caccioppoli Complesso Monte
More informationLecture Notes Math 371: Algebra (Fall 2006) by Nathanael Leedom Ackerman
Lecture Notes Math 371: Algebra (Fall 2006) by Nathanael Leedom Ackerman October 31, 2006 TALK SLOWLY AND WRITE NEATLY!! 1 0.1 Symbolic Adjunction of Roots When dealing with subfields of C it is easy to
More informationPolynomial interpolation over finite fields and applications to list decoding of Reed-Solomon codes
Polynomial interpolation over finite fields and applications to list decoding of Reed-Solomon codes Roberta Barbi December 17, 2015 Roberta Barbi List decoding December 17, 2015 1 / 13 Codes Let F q be
More informationStable Border Bases for Ideals of Points arxiv: v2 [math.ac] 16 Oct 2007
Stable Border Bases for Ideals of Points arxiv:0706.2316v2 [math.ac] 16 Oct 2007 John Abbott, Claudia Fassino, Maria-Laura Torrente Abstract Let X be a set of points whose coordinates are known with limited
More informationA Combinatorial Approach to Involution and δ-regularity II: Structure Analysis of Polynomial Modules with Pommaret Bases
AAECC manuscript No. (will be inserted by the editor) A Combinatorial Approach to Involution and δ-regularity II: Structure Analysis of Polynomial Modules with Pommaret Bases Werner M. Seiler AG Computational
More informationCOMPLEX VARIETIES AND THE ANALYTIC TOPOLOGY
COMPLEX VARIETIES AND THE ANALYTIC TOPOLOGY BRIAN OSSERMAN Classical algebraic geometers studied algebraic varieties over the complex numbers. In this setting, they didn t have to worry about the Zariski
More informationComputing Minimal Polynomial of Matrices over Algebraic Extension Fields
Bull. Math. Soc. Sci. Math. Roumanie Tome 56(104) No. 2, 2013, 217 228 Computing Minimal Polynomial of Matrices over Algebraic Extension Fields by Amir Hashemi and Benyamin M.-Alizadeh Abstract In this
More informationFOUNDATIONS OF ALGEBRAIC GEOMETRY CLASS 41
FOUNDATIONS OF ALGEBRAIC GEOMETRY CLASS 41 RAVI VAKIL CONTENTS 1. Normalization 1 2. Extending maps to projective schemes over smooth codimension one points: the clear denominators theorem 5 Welcome back!
More informationCompatibly split subvarieties of Hilb n (A 2 k)
Compatibly split subvarieties of Hilb n (A 2 k) Jenna Rajchgot MSRI Combinatorial Commutative Algebra December 3-7, 2012 Throughout this talk, let k be an algebraically closed field of characteristic p
More informationLesson 14 Properties of Groebner Bases
Lesson 14 Properties of Groebner Bases I. Groebner Bases Yield Unique Remainders Theorem Let be a Groebner basis for an ideal, and let. Then there is a unique with the following properties (i) No term
More informationThis is an auxiliary note; its goal is to prove a form of the Chinese Remainder Theorem that will be used in [2].
Witt vectors. Part 1 Michiel Hazewinkel Sidenotes by Darij Grinberg Witt#5c: The Chinese Remainder Theorem for Modules [not completed, not proofread] This is an auxiliary note; its goal is to prove a form
More informationERRATA. Abstract Algebra, Third Edition by D. Dummit and R. Foote (most recently revised on March 4, 2009)
ERRATA Abstract Algebra, Third Edition by D. Dummit and R. Foote (most recently revised on March 4, 2009) These are errata for the Third Edition of the book. Errata from previous editions have been fixed
More informationINDRANIL BISWAS AND GEORG HEIN
GENERALIZATION OF A CRITERION FOR SEMISTABLE VECTOR BUNDLES INDRANIL BISWAS AND GEORG HEIN Abstract. It is known that a vector bundle E on a smooth projective curve Y defined over an algebraically closed
More informationIntroduction to Arithmetic Geometry Fall 2013 Lecture #18 11/07/2013
18.782 Introduction to Arithmetic Geometry Fall 2013 Lecture #18 11/07/2013 As usual, all the rings we consider are commutative rings with an identity element. 18.1 Regular local rings Consider a local
More informationI. Duality. Macaulay F. S., The Algebraic Theory of Modular Systems, Cambridge Univ. Press (1916);
I. Duality Macaulay F. S., On the Resolution of a given Modular System into Primary Systems including some Properties of Hilbert Numbers, Math. Ann. 74 (1913), 66 121; Macaulay F. S., The Algebraic Theory
More informationSystems of linear equations. We start with some linear algebra. Let K be a field. We consider a system of linear homogeneous equations over K,
Systems of linear equations We start with some linear algebra. Let K be a field. We consider a system of linear homogeneous equations over K, f 11 t 1 +... + f 1n t n = 0, f 21 t 1 +... + f 2n t n = 0,.
More informationMATH 101B: ALGEBRA II PART A: HOMOLOGICAL ALGEBRA
MATH 101B: ALGEBRA II PART A: HOMOLOGICAL ALGEBRA These are notes for our first unit on the algebraic side of homological algebra. While this is the last topic (Chap XX) in the book, it makes sense to
More informationRings If R is a commutative ring, a zero divisor is a nonzero element x such that xy = 0 for some nonzero element y R.
Rings 10-26-2008 A ring is an abelian group R with binary operation + ( addition ), together with a second binary operation ( multiplication ). Multiplication must be associative, and must distribute over
More informationGröbner Bases for Noncommutative Polynomials
Gröbner Bases for Noncommutative Polynomials Arjeh M. Cohen 8 January 2007 first lecture of Three aspects of exact computation a tutorial at Mathematics: Algorithms and Proofs (MAP) Leiden, January 8 12,
More informationSylvester Matrix and GCD for Several Univariate Polynomials
Sylvester Matrix and GCD for Several Univariate Polynomials Manuela Wiesinger-Widi Doctoral Program Computational Mathematics Johannes Kepler University Linz 4040 Linz, Austria manuela.wiesinger@dk-compmath.jku.at
More informationTangent cone algorithm for homogenized differential operators
Tangent cone algorithm for homogenized differential operators Michel Granger a Toshinori Oaku b Nobuki Takayama c a Université d Angers, Bd. Lavoisier, 49045 Angers cedex 01, France b Tokyo Woman s Christian
More informationComputational Invariant Theory
Computational Invariant Theory Gregor Kemper Technische Universität München Tutorial at ISSAC, München, July 25, 2010 moments a i,j := x i y j f(x, y)dx dy I moment invariants I 1 = a 00 (a 20 + a 02 )
More informationADVANCED TOPICS IN ALGEBRAIC GEOMETRY
ADVANCED TOPICS IN ALGEBRAIC GEOMETRY DAVID WHITE Outline of talk: My goal is to introduce a few more advanced topics in algebraic geometry but not to go into too much detail. This will be a survey of
More information2.4. Solving ideal problems by Gröbner bases
Computer Algebra, F.Winkler, WS 2010/11 2.4. Solving ideal problems by Gröbner bases Computation in the vector space of polynomials modulo an ideal The ring K[X] /I of polynomials modulo the ideal I is
More informationMath 145. Codimension
Math 145. Codimension 1. Main result and some interesting examples In class we have seen that the dimension theory of an affine variety (irreducible!) is linked to the structure of the function field in
More informationFOUNDATIONS OF ALGEBRAIC GEOMETRY CLASS 37
FOUNDATIONS OF ALGEBRAIC GEOMETRY CLASS 37 RAVI VAKIL CONTENTS 1. Motivation and game plan 1 2. The affine case: three definitions 2 Welcome back to the third quarter! The theme for this quarter, insofar
More information