A mod p 3 analogue of a theorem of Gauss on binomial coefficients
|
|
- Paul Joseph
- 5 years ago
- Views:
Transcription
1 A mod p 3 analogue of a theorem of Gauss on binomial coefficients Dalhousie University, Halifax, Canada ELAZ, Schloß Schney, August 16, 01
2 Joint work with John B. Cosgrave Dublin, Ireland
3 We begin with a table: Mod p3 analogue
4 We begin with a table: Mod p3 analogue
5 We begin with a table: p ( p 1 ) p 1 (mod p) p 1 (mod 4)
6 Add in sums of squares: p ( p 1 ) p 1 (mod p) a b p 1 (mod 4), p = a + b.
7 Reformulating the table: ( p ) p 1 (mod p) < p a b p 1 (mod 4), p = a + b.
8 1. Introduction The table is an illustration of the following celebrated result: Theorem 1 (Gauss, 188) Let p 1 (mod 4) be a prime and write p = a + b, a 1 (mod 4). Then ( p 1 ) p 1 a 4 (mod p).
9 1. Introduction The table is an illustration of the following celebrated result: Theorem 1 (Gauss, 188) Let p 1 (mod 4) be a prime and write p = a + b, a 1 (mod 4). Then ( p 1 ) p 1 a 4 (mod p). Several different proofs are known, some using Jacobsthal sums".
10 Goal: Extend this to a congruence mod p.
11 Goal: Extend this to a congruence mod p. Need Fermat quotients: For m Z, m, and p m, define q p (m) := mp 1 1. p
12 Goal: Extend this to a congruence mod p. Need Fermat quotients: For m Z, m, and p m, define q p (m) := mp 1 1. p Beukers (1984) conjectured, and Chowla, Dwork & Evans (1986) proved: Theorem (Chowla, Dwork, Evans) Let p and a be as before. Then ( p 1 ) p 1 ( a a)( p pq p() ) (mod p ). 4
13 Goal: Extend this to a congruence mod p. Need Fermat quotients: For m Z, m, and p m, define q p (m) := mp 1 1. p Beukers (1984) conjectured, and Chowla, Dwork & Evans (1986) proved: Theorem (Chowla, Dwork, Evans) Let p and a be as before. Then ( p 1 ) p 1 ( a a)( p pq p() ) (mod p ). 4 Application: Search for Wilson primes.
14 . Gauss Factorials Recall Wilson s Theorem: p is a prime if and only if (p 1)! 1 (mod p).
15 . Gauss Factorials Recall Wilson s Theorem: p is a prime if and only if Define the Gauss factorial (p 1)! 1 (mod p). N n! = 1 j N gcd(j,n)=1 j.
16 . Gauss Factorials Recall Wilson s Theorem: p is a prime if and only if Define the Gauss factorial (p 1)! 1 (mod p). N n! = 1 j N gcd(j,n)=1 j. Theorem 3 (Gauss) For any integer n, { 1 (mod n) for n =, 4, p α, or p α, (n 1) n! 1 (mod n) otherwise, where p is an odd prime and α is a positive integer.
17 Recall Gauss Theorem: ( ) p 1! ) ) a (mod p).! (( p 1 4
18 Recall Gauss Theorem: ( ) p 1! ) ) a (mod p).! (( p 1 4 Can we have something like this for p in place of p, using Gauss factorials?
19 Recall Gauss Theorem: ( ) p 1! ) ) a (mod p).! (( p 1 4 Can we have something like this for p in place of p, using Gauss factorials? Idea: Use the mod p extension by Chowla et al.
20 Recall Gauss Theorem: ( ) p 1! ) ) a (mod p).! (( p 1 4 Can we have something like this for p in place of p, using Gauss factorials? Idea: Use the mod p extension by Chowla et al. Main technical device: We can show that ( p ) ( ) 1! (p 1)! p 1 p 1! 1 + p 1 p p p 1 j=1 1 j (mod p ).
21 We can derive a similar congruence for ( p ) 1! (mod p ). 4 p
22 We can derive a similar congruence for ( p ) 1! (mod p ). 4 p Also used is the congruence p 1 j=1 1 j q p () (mod p), and other similar congruences due to Emma Lehmer (1938) and others before her.
23 We can derive a similar congruence for ( p ) 1! (mod p ). 4 p Also used is the congruence p 1 j=1 1 j q p () (mod p), and other similar congruences due to Emma Lehmer (1938) and others before her. Altogether we have, after simplifying, ( ) p 1! ( p 1 ) p 1 ( ( ) ) p 1 p pq p() 4 p! (mod p ).
24 Combining this with the theorem of Chowla, Dwork & Evans: Theorem 4 Let p and a be as before. Then ) ( p 1 ( ( p 1 4 ) p! p! ) a p a (mod p ).
25 Combining this with the theorem of Chowla, Dwork & Evans: Theorem 4 Let p and a be as before. Then ) ( p 1 ( ( p 1 4 ) p! p! ) a p a (mod p ). Hopeless to conjecture an extension of the theorem of Chowla et al., but easily possible for the theorem above.
26 3. Extensions modulo p 3 By numerical experimentation we first conjectured Theorem 5 Let p and a be as before. Then ) ( p 3 1 ( ( p ) p! p! ) a p a p 8a 3 (mod p 3 ). (Proof later).
27 3. Extensions modulo p 3 By numerical experimentation we first conjectured Theorem 5 Let p and a be as before. Then ) ( p 3 1 ( ( p ) p! p! ) a p a p 8a 3 (mod p 3 ). (Proof later). Using more complicated congruences than the ones leading to Theorem 4 (but the same ideas), and going backwards, we obtain
28 Theorem 6 (Main result) Let p and a be as before. Then ( p 1 ) p 1 (a 4 ) p pa 8a 3 ( ( pq p() p E p 3 q p () )) (mod p 3 ).
29 Theorem 6 (Main result) Let p and a be as before. Then ( p 1 ) p 1 (a 4 ) p pa 8a 3 ( ( pq p() p E p 3 q p () )) (mod p 3 ). Here E p 3 is the Euler number defined by e t + e t = n=0 E n n! tn ( t < π).
30 Theorem 6 (Main result) Let p and a be as before. Then ( p 1 ) p 1 (a 4 ) p pa 8a 3 ( ( pq p() p E p 3 q p () )) (mod p 3 ). Here E p 3 is the Euler number defined by e t + e t = n=0 How can we prove Theorem 5? E n n! tn ( t < π).
31 Theorem 6 (Main result) Let p and a be as before. Then ( p 1 ) p 1 (a 4 ) p pa 8a 3 ( ( pq p() p E p 3 q p () )) (mod p 3 ). Here E p 3 is the Euler number defined by e t + e t = n=0 E n n! tn ( t < π). How can we prove Theorem 5? By further experimentation we first conjectured, and then proved the following generalization.
32 Theorem 7 Let p and a be as before and let α be an integer. Then ) ( p α 1 ( ( p α 1 4 ) p! p! ) a 1 p a 1 p 8a 3
33 Theorem 7 Let p and a be as before and let α be an integer. Then ) ( p α 1 ( ( p α 1 4 ) p! p! ) a 1 p a 1 p 8a 3 p 3 (a) 5
34 Theorem 7 Let p and a be as before and let α be an integer. Then ) ( p α 1 ( ( p α 1 4 ) p! p! ) a 1 p a 1 p 8a 3 p 3 (a) 5 5 p 4 (a) 7
35 Theorem 7 Let p and a be as before and let α be an integer. Then ) ( p α 1 ( ( p α 1 4 ) p! p! ) a 1 14 p 5 (a) 9 p a 1 p 8a 3 p 3 (a) 5 5 p 4 (a) 7
36 Theorem 7 Let p and a be as before and let α be an integer. Then ) ( p α 1 ( ( p α 1 4 ) p! p! ) a 1 p 5 p a 1 p 8a 3 p 3 (a) 5 5 p 4 (a) 7 p α 1 14 (a) 9... C α (a) α 1 (mod p α ).
37 Theorem 7 Let p and a be as before and let α be an integer. Then ) ( p α 1 ( ( p α 1 4 ) p! p! ) a 1 p 5 p a 1 p 8a 3 p 3 (a) 5 5 p 4 (a) 7 p α 1 14 (a) 9... C α (a) α 1 (mod p α ). Here C n := 1 an integer. n+1 ( n n ) is the nth Catalan number which is always
38 Theorem 7 Let p and a be as before and let α be an integer. Then ) ( p α 1 ( ( p α 1 4 ) p! p! ) a 1 p 5 p a 1 p 8a 3 p 3 (a) 5 5 p 4 (a) 7 p α 1 14 (a) 9... C α (a) α 1 (mod p α ). Here C n := 1 an integer. n+1 ( n n ) is the nth Catalan number which is always Theorem 5 is obviously a special case of Theorem 7.
39 4. Main Ingredients in the Proof The Jacobi sum J(χ, ψ) = χ(j)ψ(1 j), j mod p where χ and ψ are characters modulo p.
40 4. Main Ingredients in the Proof The Jacobi sum J(χ, ψ) = j mod p χ(j)ψ(1 j), where χ and ψ are characters modulo p. Fix a primitive root g mod p; let χ be a character of order 4 such that χ(g) = i.
41 4. Main Ingredients in the Proof The Jacobi sum J(χ, ψ) = j mod p χ(j)ψ(1 j), where χ and ψ are characters modulo p. Fix a primitive root g mod p; let χ be a character of order 4 such that χ(g) = i. Define integers a, b by ( ) p = a +b, a (mod 4), b a g (p 1)/4 (mod p). p
42 4. Main Ingredients in the Proof The Jacobi sum J(χ, ψ) = j mod p χ(j)ψ(1 j), where χ and ψ are characters modulo p. Fix a primitive root g mod p; let χ be a character of order 4 such that χ(g) = i. Define integers a, b by ( ) p = a +b, a (mod 4), b a g (p 1)/4 (mod p). p These are uniquely defined, differ from a and b of Gauss theorem only (possibly) in sign.
43 Then J(χ, χ) = ( 1) p 1 4 (a + ib ), J(χ 3, χ 3 ) = ( 1) p 1 4 (a ib ),
44 Then J(χ, χ) = ( 1) p 1 4 (a + ib ), J(χ 3, χ 3 ) = ( 1) p 1 4 (a ib ), On the other hand, J(χ, χ) 0 (mod p), J(χ 3, χ 3 ) = Γ p(1 1 ) Γ p (1 1 4 ). These are deep results, related to the Gross-Koblitz formula" (see, e.g., Gauss and Jacobi Sums by B. Berndt, R. Evans and K. Williams).
45 Γ p (z) is the p-adic gamma function defined by F(n) := ( 1) n 0<j<n p j Γ p (z) = lim n z F(n) (z Z p ), where n runs through any sequence of positive integers p-adically approaching z. j,
46 In particular, ( 1) p 1 4 (a ib ) = J(χ 3, χ 3 ) = Γ p(1 1 ) Γ p (1 1 4 ) Γ p(1 + pα 1 ) Γ p (1 + pα 1 4 ) (mod pα ) = F(1 + pα 1 ) F(1 + pα 1 = 4 ) ( ) p α 1 ( ( p α 1 4 ) p! p! ).
47 Raise to the power α: ( 1) p 1 4 (a + ib ) = J(χ, χ) 0 (mod p)
48 Raise to the power α: ( 1) p 1 4 (a + ib ) = J(χ, χ) 0 (mod p) (a + ib ) α 0 (mod p α ).
49 Raise to the power α: ( 1) p 1 4 (a + ib ) = J(χ, χ) 0 (mod p) (a + ib ) α 0 (mod p α ). Expand the left-hand side; get binomial coefficients;
50 Raise to the power α: ( 1) p 1 4 (a + ib ) = J(χ, χ) 0 (mod p) (a + ib ) α 0 (mod p α ). Expand the left-hand side; get binomial coefficients; separate real and imaginary parts;
51 Raise to the power α: ( 1) p 1 4 (a + ib ) = J(χ, χ) 0 (mod p) (a + ib ) α 0 (mod p α ). Expand the left-hand side; get binomial coefficients; separate real and imaginary parts; use the combinatorial identity (k = 0, 1,..., n 1) k j=0 ( 1) j j + 1 ( j j )( ) ( n + j k n 1 k = k j k ) ;
52 Raise to the power α: ( 1) p 1 4 (a + ib ) = J(χ, χ) 0 (mod p) (a + ib ) α 0 (mod p α ). Expand the left-hand side; get binomial coefficients; separate real and imaginary parts; use the combinatorial identity (k = 0, 1,..., n 1) k j=0 ( 1) j j + 1 ( j j )( ) ( n + j k n 1 k = k j k putting everything together, we obtain Theorem 7. ) ;
53 5. A Jacobi Analogue Let p 1 (mod 6). Then we can write 4p = r + 3s, r 1 (mod 3), 3 s, which determines r uniquely.
54 5. A Jacobi Analogue Let p 1 (mod 6). Then we can write 4p = r + 3s, r 1 (mod 3), 3 s, which determines r uniquely. In analogy to Gauss Theorem 1 we have Theorem 8 (Jacobi, 1837) Let p and r be as above. Then ( (p 1) ) 3 p 1 r 3 (mod p).
55 5. A Jacobi Analogue Let p 1 (mod 6). Then we can write 4p = r + 3s, r 1 (mod 3), 3 s, which determines r uniquely. In analogy to Gauss Theorem 1 we have Theorem 8 (Jacobi, 1837) Let p and r be as above. Then ( (p 1) ) 3 p 1 r 3 (mod p). This was generalized to mod p independently by Evans (unpublished, 1985) and Yeung (1989):
56 Theorem 9 (Evans; Yeung) Let p and r be as above. Then ( (p 1) ) 3 p 1 r + p r 3 (mod p ).
57 Theorem 9 (Evans; Yeung) Let p and r be as above. Then ( (p 1) ) 3 p 1 r + p r 3 (mod p ). With methods similar to those in the first part of this talk, we proved Theorem 10 Let p and r be as above. Then ( (p 1) ) 3 p 1 ( r + 3 ) pr p + (1 r ) p B p ( 13 ) (mod p 3 ). Here B n (x) is the nth Bernoulli polynomial.
58 6. More on Gauss Factorials Write out the factorial (p 1)!, exploit symmetry mod p: ( 1... p 1 p+1... (p 1) p 1 )!( 1) p 1 ( ) p 1! (mod p).
59 6. More on Gauss Factorials Write out the factorial (p 1)!, exploit symmetry mod p: ( 1... p 1 p+1... (p 1) p 1 )!( 1) p 1 Thus, with Wilson s Theorem, ( p 1 )! ( 1) p+1 (mod p). ( ) p 1! (mod p).
60 6. More on Gauss Factorials Write out the factorial (p 1)!, exploit symmetry mod p: ( 1... p 1 p+1... (p 1) p 1 )!( 1) p 1 Thus, with Wilson s Theorem, ( p 1 )! ( 1) p+1 (mod p). ( ) p 1! (mod p). This was apparently first observed by Lagrange (1773).
61 6. More on Gauss Factorials Write out the factorial (p 1)!, exploit symmetry mod p: ( 1... p 1 p+1... (p 1) p 1 )!( 1) p 1 Thus, with Wilson s Theorem, ( p 1 )! ( 1) p+1 (mod p). ( ) p 1! (mod p). This was apparently first observed by Lagrange (1773). For p 1 (mod 4) the RHS is 1, so (( ) ) ord p 1 p! = 4 for p 1 (mod 4).
62 In the case p 3 (mod 4) we get ( p 1 )! ±1 (mod p).
63 In the case p 3 (mod 4) we get ( p 1 What is the sign on the right? )! ±1 (mod p).
64 In the case p 3 (mod 4) we get ( p 1 What is the sign on the right? Theorem 11 (Mordell, 1961) For a prime p 3 (mod 4), ( p 1 )! ±1 (mod p). )! 1 (mod p) h( p) 1 (mod 4), where h( p) is the class number of Q( p).
65 In the case p 3 (mod 4) we get ( p 1 What is the sign on the right? Theorem 11 (Mordell, 1961) For a prime p 3 (mod 4), ( p 1 )! ±1 (mod p). )! 1 (mod p) h( p) 1 (mod 4), where h( p) is the class number of Q( p). Discovered independently by Chowla. This completely determines the order mod p of ( ) p 1!.
66 Now consider the two halves of the product 1 p 1 p+1 (p 1) and denote them, respectively, by Π () 1, Π().
67 Now consider the two halves of the product 1 p 1 p+1 (p 1) and denote them, respectively, by By Wilson s theorem: Π () 1, Π(). Π () 1 Π() 1 (mod p),
68 Now consider the two halves of the product 1 p 1 p+1 (p 1) and denote them, respectively, by By Wilson s theorem: and by symmetry: Π () 1, Π(). Π () 1 Π() 1 (mod p), Π () ( 1) p 1 Π () 1 (mod p).
69 What can we say about the three partial products Π (3) 1, Π(3), Π(3) 3 obtained by dividing the entire product (p 1)! into three equal parts?
70 What can we say about the three partial products Π (3) 1, Π(3), Π(3) 3 obtained by dividing the entire product (p 1)! into three equal parts? We require p 1 (mod 3); in fact, p 1 (mod 6).
71 What can we say about the three partial products Π (3) 1, Π(3), Π(3) 3 obtained by dividing the entire product (p 1)! into three equal parts? We require p 1 (mod 3); in fact, p 1 (mod 6). Then Π (3) 1 = 1 p 1 3, Π(3) = p+ 3 p 3, Π (3) 3 = p+1 3 (p 1).
72 What can we say about the three partial products Π (3) 1, Π(3), Π(3) 3 obtained by dividing the entire product (p 1)! into three equal parts? We require p 1 (mod 3); in fact, p 1 (mod 6). Then Π (3) 1 = 1 p 1 3, Π(3) = p+ 3 p 3, Π (3) 3 = p+1 3 (p 1). Once again there is an obvious symmetry: Π (3) 3 Π (3) 1 (mod p), (without a power of 1 since p 1 3 is always even.)
73 What can we say about the three partial products Π (3) 1, Π(3), Π(3) 3 obtained by dividing the entire product (p 1)! into three equal parts? We require p 1 (mod 3); in fact, p 1 (mod 6). Then Π (3) 1 = 1 p 1 3, Π(3) = p+ 3 p 3, Π (3) 3 = p+1 3 (p 1). Once again there is an obvious symmetry: Π (3) 3 Π (3) 1 (mod p), (without a power of 1 since p 1 3 is always even.) No obvious relation between Π (3) 1 and the middle third" Π (3).
74 Natural extension: For any M and for a prime p 1 (mod M), divide (p 1)! into the products
75 Natural extension: For any M and for a prime p 1 (mod M), divide (p 1)! into the products Π (M) j = p 1 M i=1 ( (j 1) p 1 M + i ), (j = 1,,..., M).
76 Natural extension: For any M and for a prime p 1 (mod M), divide (p 1)! into the products Π (M) j = p 1 M i=1 Once again, clear that ( (j 1) p 1 M + i ), (j = 1,,..., M). Π (M) M j ±Π (M) j (mod p), j = 1,,..., M 1.
77 Natural extension: For any M and for a prime p 1 (mod M), divide (p 1)! into the products Π (M) j = p 1 M i=1 Once again, clear that Example: ( (j 1) p 1 M + i ), (j = 1,,..., M). Π (M) M j ±Π (M) j (mod p), j = 1,,..., M 1.
78 p Π (3) 1 Π (3) Π (3) 3 p Π (4) 1 Π (4) Π (4) 3 Π (4)
79 p Π (3) 1 Π (3) Π (3) 3 p Π (4) 1 Π (4) Π (4) 3 Π (4) We observe: The obvious symmetries.
80 p Π (3) 1 Π (3) Π (3) 3 p Π (4) 1 Π (4) Π (4) 3 Π (4) We observe: The obvious symmetries. Π (3) 1 Π (3) (mod p) for p = 7 and p = 61.
81 Are these last cases just coincidences?
82 Are these last cases just coincidences? It turns out: Π (3) 1 Π (3) (mod p) also for p = 331, p = 547, p = 1951, and further relatively rare primes (explained below).
83 Are these last cases just coincidences? It turns out: Π (3) 1 Π (3) (mod p) also for p = 331, p = 547, p = 1951, and further relatively rare primes (explained below). In contrast: No primes p for which Π (3) 1 Π (3) (mod p), p 1 (mod 6), or Π (4) 1 ±Π (4) (mod p), p 1 (mod 4).
84 Are these last cases just coincidences? It turns out: Π (3) 1 Π (3) (mod p) also for p = 331, p = 547, p = 1951, and further relatively rare primes (explained below). In contrast: No primes p for which Π (3) 1 Π (3) (mod p), p 1 (mod 6), or Π (4) 1 ±Π (4) (mod p), p 1 (mod 4). The theorems of Gauss and Jacobi can be used to explain this:
85 Consider the quotient Q 4 (p) := Π(4) Π (4) 1
86 Consider the quotient Q 4 (p) := Π(4) Π (4) 1 = Π(4) 1 Π(4) ( ) Π (4) 1
87 Consider the quotient Q 4 (p) := Π(4) Π (4) 1 = Π(4) 1 Π(4) ( Π (4) 1 ) = p 1 (! ) p 1 4!
88 Consider the quotient Q 4 (p) := Π(4) Π (4) 1 = Π(4) 1 Π(4) ( Π (4) 1 ) = p 1 (! ) = p 1 4! ( p 1 ) p 1. 4
89 Consider the quotient Q 4 (p) := Π(4) Π (4) 1 Recall Gauss theorem: = Π(4) 1 Π(4) ( Π (4) 1 ( p 1 p 1 4 ) a ) = p 1 (! ) = p 1 4! (mod p), ( p 1 ) p 1. 4 where p 1 (mod 4), p = a + b, a 1 (mod 4).
90 Consider the quotient Q 4 (p) := Π(4) Π (4) 1 Recall Gauss theorem: = Π(4) 1 Π(4) ( Π (4) 1 ( p 1 p 1 4 ) a ) = p 1 (! ) = p 1 4! (mod p), ( p 1 ) p 1. 4 where p 1 (mod 4), p = a + b, a 1 (mod 4). It follows easily that Π (4) ±Π (4) 1 (mod p) for all p 1 (mod 4).
91 Consider the quotient Q 4 (p) := Π(4) Π (4) 1 Recall Gauss theorem: = Π(4) 1 Π(4) ( Π (4) 1 ( p 1 p 1 4 ) a ) = p 1 (! ) = p 1 4! (mod p), ( p 1 ) p 1. 4 where p 1 (mod 4), p = a + b, a 1 (mod 4). It follows easily that Π (4) ±Π (4) 1 (mod p) for all p 1 (mod 4). Similarly, Jacobi s theorem implies that Π (3) Π (3) 1 (mod p) for all p 1 (mod 6).
92 A number of further consequences can be derived from these classical theorems.
93 A number of further consequences can be derived from these classical theorems. Two samples: Corollary 1 For a prime p 1 (mod 6) we have Π (3) Π (3) 1 (mod p) p = 7x + 7x + 7, x Z.
94 A number of further consequences can be derived from these classical theorems. Two samples: Corollary 1 For a prime p 1 (mod 6) we have Π (3) Π (3) 1 (mod p) p = 7x + 7x + 7, x Z. The first such primes are 7, 61 (seen earlier), 331, 547, 1951.
95 Corollary 13 Let p 1 (mod 4). Then (a) p 1 4! 1 (mod p) only if p = 5.
96 Corollary 13 Let p 1 (mod 4). Then (a) p 1 4 (b)! 1 (mod p) only if p = 5. ( ) k p 1 4! 1 (mod p) for k = 1,, 4.
97 Corollary 13 Let p 1 (mod 4). Then (a) p 1 4 ( p 1 (b) (c)! 1 (mod p) only if p = 5. ) k 4! 1 (mod p) for k = 1,, 4. ( ) 8 p 1 4! 1 (mod p) holds for p = 17, 41, 3361, 46817, 65081,...
98 Corollary 13 Let p 1 (mod 4). Then (a) p 1 4 ( p 1 (b) (c)! 1 (mod p) only if p = 5. ) k 4! 1 (mod p) for k = 1,, 4. ( ) 8 p 1 4! 1 (mod p) holds for p = 17, 41, 3361, 46817, 65081,... Part (c) is related to the solution of a certain Pell equation.
99 How are we doing with time? Salvador Dalí, The Persistence of Memory, 1931.
100 7. Composite Moduli Recall Gauss generalization of Wilson s theorem, the prototype of all composite modulus extensions: { 1 (mod n) for n =, 4, p α, or p α, (n 1) n! 1 (mod n) otherwise, where p is an odd prime and α is a positive integer.
101 7. Composite Moduli Recall Gauss generalization of Wilson s theorem, the prototype of all composite modulus extensions: { 1 (mod n) for n =, 4, p α, or p α, (n 1) n! 1 (mod n) otherwise, where p is an odd prime and α is a positive integer. Everything we did before can be extended to composite moduli.
102 7. Composite Moduli Recall Gauss generalization of Wilson s theorem, the prototype of all composite modulus extensions: { 1 (mod n) for n =, 4, p α, or p α, (n 1) n! 1 (mod n) otherwise, where p is an odd prime and α is a positive integer. Everything we did before can be extended to composite moduli. E.g., the multiplicative orders of ( n 1 ) n! modulo n were completely determined; only orders 1,, 4 occur. (JBC & KD, 008).
103 Next, divide the product (n 1) n! into M partial products:
104 Next, divide the product (n 1) n! into M partial products: For n 1 (mod M), set Π (M) j := i I (M) j where, for j = 1,,..., M, I (M) j := { i (j 1) n 1 M i, (j = 1,,..., M), + 1 i j n 1 M, gcd(i, n) = 1}.
105 Next, divide the product (n 1) n! into M partial products: For n 1 (mod M), set Π (M) j := i I (M) j where, for j = 1,,..., M, I (M) j := { i (j 1) n 1 M i, (j = 1,,..., M), + 1 i j n 1 M, gcd(i, n) = 1}. Dependence on n is implied in the notation;
106 Next, divide the product (n 1) n! into M partial products: For n 1 (mod M), set Π (M) j := i I (M) j where, for j = 1,,..., M, I (M) j := { i (j 1) n 1 M i, (j = 1,,..., M), + 1 i j n 1 M, gcd(i, n) = 1}. Dependence on n is implied in the notation; When n = p: reduces to previous case.
107 Example: n Π (3) 1 Π (3) Π (3) 3 n Π (4) 1 Π (4) Π (4) 3 Π (4)
108 Example: n Π (3) 1 Π (3) Π (3) 3 n Π (4) 1 Π (4) Π (4) 3 Π (4)
109 Example: n Π (3) 1 Π (3) Π (3) 3 n Π (4) 1 Π (4) Π (4) 3 Π (4) We see: In contrast to prime case, it can happen that all partial products are congruent to each other.
110 We pause to consider the number of elements in our subintervals: φ M,j (n) := #I (M) j. (Called totatives by J. J. Sylvester and later D. H. Lehmer).
111 We pause to consider the number of elements in our subintervals: φ M,j (n) := #I (M) j. (Called totatives by J. J. Sylvester and later D. H. Lehmer). When n = p is a prime, then φ M,j (n) = p 1 M for all j.
112 We pause to consider the number of elements in our subintervals: φ M,j (n) := #I (M) j. (Called totatives by J. J. Sylvester and later D. H. Lehmer). When n = p is a prime, then φ M,j (n) = p 1 M for all j. When M = 1, then φ 1,1 (n) = φ(n).
113 We pause to consider the number of elements in our subintervals: φ M,j (n) := #I (M) j. (Called totatives by J. J. Sylvester and later D. H. Lehmer). When n = p is a prime, then φ M,j (n) = p 1 M for all j. When M = 1, then φ 1,1 (n) = φ(n). When M =, then φ,1 (n) = φ, (n) = 1 φ(n).
114 We pause to consider the number of elements in our subintervals: φ M,j (n) := #I (M) j. (Called totatives by J. J. Sylvester and later D. H. Lehmer). When n = p is a prime, then φ M,j (n) = p 1 M for all j. When M = 1, then φ 1,1 (n) = φ(n). When M =, then φ,1 (n) = φ, (n) = 1 φ(n). In general, the situation is less straightforward.
115 We pause to consider the number of elements in our subintervals: φ M,j (n) := #I (M) j. (Called totatives by J. J. Sylvester and later D. H. Lehmer). When n = p is a prime, then φ M,j (n) = p 1 M for all j. When M = 1, then φ 1,1 (n) = φ(n). When M =, then φ,1 (n) = φ, (n) = 1 φ(n). In general, the situation is less straightforward. E.g., for n = 4: φ 3,1 (n) = φ 3,3 (n) = 1, but φ 3, (n) = 0.
116 When do we have equal distribution?
117 When do we have equal distribution? Theorem 14 (Lehmer, 1955) Let M and n 1 (mod M). If n has at least one prime factor p 1 (mod M), then φ M,j (n) = 1 M φ(n), (j = 1,,..., M).
118 When do we have equal distribution? Theorem 14 (Lehmer, 1955) Let M and n 1 (mod M). If n has at least one prime factor p 1 (mod M), then φ M,j (n) = 1 M φ(n), (j = 1,,..., M). Note: Condition is sufficient, but not necessary.
119 When Are the Partial Products Congruent to each other?
120 When Are the Partial Products Congruent to each other? Return to our table: n Π (3) 1 Π (3) Π (3) 3 n Π (4) 1 Π (4) Π (4) 3 Π (4)
121 When Are the Partial Products Congruent to each other? Return to our table: n Π (3) 1 Π (3) Π (3) 3 n Π (4) 1 Π (4) Π (4) 3 Π (4) Note: 91 = 7 13, 65 = 5 13, 85 = 5 17.
122 This observation holds in general:
123 This observation holds in general: Theorem 15 Let M and n 1 (mod M). If n has at least two distinct prime factors 1 (mod M), then Π (M) j ( ) n 1 M! (mod n), j = 1,,..., M. n
124 This observation holds in general: Theorem 15 Let M and n 1 (mod M). If n has at least two distinct prime factors 1 (mod M), then Π (M) j ( ) n 1 M! (mod n), j = 1,,..., M. n Result is best possible.
125 This observation holds in general: Theorem 15 Let M and n 1 (mod M). If n has at least two distinct prime factors 1 (mod M), then Π (M) j ( ) n 1 M! (mod n), j = 1,,..., M. n Result is best possible. On the other hand, condition is sufficient but not necessary.
126 Idea of proof: 1. Observe that Π (M) j = ( ) j n 1 M ( (j 1) n 1 M n! )n!, j = 1,,..., M,
127 Idea of proof: 1. Observe that Π (M) j = ( ) j n 1 M ( (j 1) n 1 M n! )n!, j = 1,,..., M,. Let n = p α q β w for p, q 1 (mod M) and gcd(pq, w) = 1.
128 Idea of proof: 1. Observe that Π (M) j = ( ) j n 1 M ( (j 1) n 1 M n! )n!, j = 1,,..., M,. Let n = p α q β w for p, q 1 (mod M) and gcd(pq, w) = Break the range of the product in ( j n 1 ) M n! into a number of products of approximately equal length, a shorter tail."
129 Idea of proof: 1. Observe that Π (M) j = ( ) j n 1 M ( (j 1) n 1 M n! )n!, j = 1,,..., M,. Let n = p α q β w for p, q 1 (mod M) and gcd(pq, w) = Break the range of the product in ( j n 1 ) M n! into a number of products of approximately equal length, a shorter tail." 4. Then evaluate the products of the first type using the Gauss-Wilson theorem (mod q β w).
130 Idea of proof: 1. Observe that Π (M) j = ( ) j n 1 M ( (j 1) n 1 M n! )n!, j = 1,,..., M,. Let n = p α q β w for p, q 1 (mod M) and gcd(pq, w) = Break the range of the product in ( j n 1 ) M n! into a number of products of approximately equal length, a shorter tail." 4. Then evaluate the products of the first type using the Gauss-Wilson theorem (mod q β w). 5. Carefully count which elements to include/exclude.
131 Idea of proof: 1. Observe that Π (M) j = ( ) j n 1 M ( (j 1) n 1 M n! )n!, j = 1,,..., M,. Let n = p α q β w for p, q 1 (mod M) and gcd(pq, w) = Break the range of the product in ( j n 1 ) M n! into a number of products of approximately equal length, a shorter tail." 4. Then evaluate the products of the first type using the Gauss-Wilson theorem (mod q β w). 5. Carefully count which elements to include/exclude. 6. Use Chinese Remainder Theorem modulo q β w and q α w.
132 In the case of at least three distinct prime factors 1 (mod M) we can say more:
133 In the case of at least three distinct prime factors 1 (mod M) we can say more: Theorem 16 Let M and n 1 (mod M). If n has at least three distinct prime factors 1 (mod M), then Π (M) j 1 (mod n), j = 1,,..., M.
134 In the case of at least three distinct prime factors 1 (mod M) we can say more: Theorem 16 Let M and n 1 (mod M). If n has at least three distinct prime factors 1 (mod M), then Π (M) j 1 (mod n), j = 1,,..., M. Method of proof is similar to that of previous result.
135 Summary: # of prime factors 1 (mod M) All Π (M) 1,..., Π (M) M : 1 have the same number of factors are congruent to each other (mod M) 3 are congruent to 1 (mod M)
136 Outlook Main task: Understand the multiplicative orders of ( ) n 1! (mod n). M n
137 Outlook Main task: Understand the multiplicative orders of ( ) n 1! (mod n). M n When M = : Completely determined.
138 Outlook Main task: Understand the multiplicative orders of ( ) n 1! (mod n). M n When M = : Completely determined. Let M 3 and n 1 (mod M).
139 Outlook Main task: Understand the multiplicative orders of ( ) n 1! (mod n). M n When M = : Completely determined. Let M 3 and n 1 (mod M). Then, when n has 3 prime factors 1 (mod M): order is always 1.
140 Outlook Main task: Understand the multiplicative orders of ( ) n 1! (mod n). M n When M = : Completely determined. Let M 3 and n 1 (mod M). Then, when n has 3 prime factors 1 (mod M): order is always 1. n has prime factors 1 (mod M): order is a divisor of M.
141 Outlook Main task: Understand the multiplicative orders of ( ) n 1! (mod n). M n When M = : Completely determined. Let M 3 and n 1 (mod M). Then, when n has 3 prime factors 1 (mod M): order is always 1. n has prime factors 1 (mod M): order is a divisor of M. n has 0 or 1 prime factor 1 (mod M): The most interesting and difficult case. Several results already published. Further work in progress.
142 Thank you Danke Mod p3 analogue
Theory of Numbers Problems
Theory of Numbers Problems Antonios-Alexandros Robotis Robotis October 2018 1 First Set 1. Find values of x and y so that 71x 50y = 1. 2. Prove that if n is odd, then n 2 1 is divisible by 8. 3. Define
More informationMath 324, Fall 2011 Assignment 7 Solutions. 1 (ab) γ = a γ b γ mod n.
Math 324, Fall 2011 Assignment 7 Solutions Exercise 1. (a) Suppose a and b are both relatively prime to the positive integer n. If gcd(ord n a, ord n b) = 1, show ord n (ab) = ord n a ord n b. (b) Let
More informationq-binomial coefficient congruences
CARMA Analysis and Number Theory Seminar University of Newcastle August 23, 2011 Tulane University, New Orleans 1 / 35 Our first -analogs The natural number n has the -analog: [n] = n 1 1 = 1 + +... n
More informationMod p 3 analogues of theorems of Gauss and Jacobi on binomial coefficients
ACTA ARITHMETICA 2.2 (200 Mo 3 analogues of theorems of Gauss an Jacobi on binomial coefficients by John B. Cosgrave (Dublin an Karl Dilcher (Halifax. Introuction. One of the most remarkable congruences
More informationPart II. Number Theory. Year
Part II Year 2017 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 2017 Paper 3, Section I 1G 70 Explain what is meant by an Euler pseudoprime and a strong pseudoprime. Show that 65 is an Euler
More informationOn Arithmetic Properties of Bell Numbers, Delannoy Numbers and Schröder Numbers
A tal given at the Institute of Mathematics, Academia Sinica (Taiwan (Taipei; July 6, 2011 On Arithmetic Properties of Bell Numbers, Delannoy Numbers and Schröder Numbers Zhi-Wei Sun Nanjing University
More informationA conjecture of Evans on Kloosterman sums
Evan P. Dummit, Adam W. Goldberg, and Alexander R. Perry 2009 Wisconsin Number Theory REU Project Notation We will make use of the following notation: p odd prime Additive character ψ : F p C, x e 2πix
More information2.3 In modular arithmetic, all arithmetic operations are performed modulo some integer.
CHAPTER 2 INTRODUCTION TO NUMBER THEORY ANSWERS TO QUESTIONS 2.1 A nonzero b is a divisor of a if a = mb for some m, where a, b, and m are integers. That is, b is a divisor of a if there is no remainder
More informationElementary Number Theory MARUCO. Summer, 2018
Elementary Number Theory MARUCO Summer, 2018 Problem Set #0 axiom, theorem, proof, Z, N. Axioms Make a list of axioms for the integers. Does your list adequately describe them? Can you make this list as
More information7. Prime Numbers Part VI of PJE
7. Prime Numbers Part VI of PJE 7.1 Definition (p.277) A positive integer n is prime when n > 1 and the only divisors are ±1 and +n. That is D (n) = { n 1 1 n}. Otherwise n > 1 is said to be composite.
More informationAn integer p is prime if p > 1 and p has exactly two positive divisors, 1 and p.
Chapter 6 Prime Numbers Part VI of PJE. Definition and Fundamental Results Definition. (PJE definition 23.1.1) An integer p is prime if p > 1 and p has exactly two positive divisors, 1 and p. If n > 1
More informationWilson s Theorem and Fermat s Little Theorem
Wilson s Theorem and Fermat s Little Theorem Wilson stheorem THEOREM 1 (Wilson s Theorem): (p 1)! 1 (mod p) if and only if p is prime. EXAMPLE: We have (2 1)!+1 = 2 (3 1)!+1 = 3 (4 1)!+1 = 7 (5 1)!+1 =
More informationMATH 310: Homework 7
1 MATH 310: Homework 7 Due Thursday, 12/1 in class Reading: Davenport III.1, III.2, III.3, III.4, III.5 1. Show that x is a root of unity modulo m if and only if (x, m 1. (Hint: Use Euler s theorem and
More informationSummary Slides for MATH 342 June 25, 2018
Summary Slides for MATH 342 June 25, 2018 Summary slides based on Elementary Number Theory and its applications by Kenneth Rosen and The Theory of Numbers by Ivan Niven, Herbert Zuckerman, and Hugh Montgomery.
More informationSOLUTIONS Math 345 Homework 6 10/11/2017. Exercise 23. (a) Solve the following congruences: (i) x (mod 12) Answer. We have
Exercise 23. (a) Solve the following congruences: (i) x 101 7 (mod 12) Answer. We have φ(12) = #{1, 5, 7, 11}. Since gcd(7, 12) = 1, we must have gcd(x, 12) = 1. So 1 12 x φ(12) = x 4. Therefore 7 12 x
More informationNumber Theory. CSS322: Security and Cryptography. Sirindhorn International Institute of Technology Thammasat University CSS322. Number Theory.
CSS322: Security and Cryptography Sirindhorn International Institute of Technology Thammasat University Prepared by Steven Gordon on 29 December 2011 CSS322Y11S2L06, Steve/Courses/2011/S2/CSS322/Lectures/number.tex,
More informationBinary quadratic forms and sums of triangular numbers
Binary quadratic forms and sums of triangular numbers Zhi-Hong Sun( ) Huaiyin Normal University http://www.hytc.edu.cn/xsjl/szh Notation: Z the set of integers, N the set of positive integers, [x] the
More informationIntroduction to Number Theory
INTRODUCTION Definition: Natural Numbers, Integers Natural numbers: N={0,1,, }. Integers: Z={0,±1,±, }. Definition: Divisor If a Z can be writeen as a=bc where b, c Z, then we say a is divisible by b or,
More informationIRREDUCIBILITY TESTS IN F p [T ]
IRREDUCIBILITY TESTS IN F p [T ] KEITH CONRAD 1. Introduction Let F p = Z/(p) be a field of prime order. We will discuss a few methods of checking if a polynomial f(t ) F p [T ] is irreducible that are
More informationNumber Theory Homework.
Number Theory Homewor. 1. The Theorems of Fermat, Euler, and Wilson. 1.1. Fermat s Theorem. The following is a special case of a result we have seen earlier, but as it will come up several times in this
More informationMathematics for Cryptography
Mathematics for Cryptography Douglas R. Stinson David R. Cheriton School of Computer Science University of Waterloo Waterloo, Ontario, N2L 3G1, Canada March 15, 2016 1 Groups and Modular Arithmetic 1.1
More informationCongruent Number Problem and Elliptic curves
Congruent Number Problem and Elliptic curves December 12, 2010 Contents 1 Congruent Number problem 2 1.1 1 is not a congruent number.................................. 2 2 Certain Elliptic Curves 4 3 Using
More informationNotes on Primitive Roots Dan Klain
Notes on Primitive Roots Dan Klain last updated March 22, 2013 Comments and corrections are welcome These supplementary notes summarize the presentation on primitive roots given in class, which differed
More informationBasic elements of number theory
Cryptography Basic elements of number theory Marius Zimand 1 Divisibility, prime numbers By default all the variables, such as a, b, k, etc., denote integer numbers. Divisibility a 0 divides b if b = a
More informationNotes on Systems of Linear Congruences
MATH 324 Summer 2012 Elementary Number Theory Notes on Systems of Linear Congruences In this note we will discuss systems of linear congruences where the moduli are all different. Definition. Given the
More informationBasic elements of number theory
Cryptography Basic elements of number theory Marius Zimand By default all the variables, such as a, b, k, etc., denote integer numbers. Divisibility a 0 divides b if b = a k for some integer k. Notation
More informationEuler s, Fermat s and Wilson s Theorems
Euler s, Fermat s and Wilson s Theorems R. C. Daileda February 17, 2018 1 Euler s Theorem Consider the following example. Example 1. Find the remainder when 3 103 is divided by 14. We begin by computing
More informationp-regular functions and congruences for Bernoulli and Euler numbers
p-regular functions and congruences for Bernoulli and Euler numbers Zhi-Hong Sun( Huaiyin Normal University Huaian, Jiangsu 223001, PR China http://www.hytc.edu.cn/xsjl/szh Notation: Z the set of integers,
More informationDefinition 6.1 (p.277) A positive integer n is prime when n > 1 and the only positive divisors are 1 and n. Alternatively
6 Prime Numbers Part VI of PJE 6.1 Fundamental Results Definition 6.1 (p.277) A positive integer n is prime when n > 1 and the only positive divisors are 1 and n. Alternatively D (p) = { p 1 1 p}. Otherwise
More informationPolynomial analogues of Ramanujan congruences for Han s hooklength formula
Polynomial analogues of Ramanujan congruences for Han s hooklength formula William J. Keith CELC, University of Lisbon Email: william.keith@gmail.com Detailed arxiv preprint: 1109.1236 Context Partition
More information198 VOLUME 46/47, NUMBER 3
LAWRENCE SOMER Abstract. Rotkiewicz has shown that there exist Fibonacci pseudoprimes having the forms p(p + 2), p(2p 1), and p(2p + 3), where all the terms in the products are odd primes. Assuming Dickson
More informationA Guide to Arithmetic
A Guide to Arithmetic Robin Chapman August 5, 1994 These notes give a very brief resumé of my number theory course. Proofs and examples are omitted. Any suggestions for improvements will be gratefully
More information9 Modular Exponentiation and Square-Roots
9 Modular Exponentiation and Square-Roots Modular arithmetic is used in cryptography. In particular, modular exponentiation is the cornerstone of what is called the RSA system. 9. Modular Exponentiation
More information7.2 Applications of Euler s and Fermat s Theorem.
7.2 Applications of Euler s and Fermat s Theorem. i) Finding and using inverses. From Fermat s Little Theorem we see that if p is prime and p a then a p 1 1 mod p, or equivalently a p 2 a 1 mod p. This
More informationLECTURE 4: CHINESE REMAINDER THEOREM AND MULTIPLICATIVE FUNCTIONS
LECTURE 4: CHINESE REMAINDER THEOREM AND MULTIPLICATIVE FUNCTIONS 1. The Chinese Remainder Theorem We now seek to analyse the solubility of congruences by reinterpreting their solutions modulo a composite
More information1 Structure of Finite Fields
T-79.5501 Cryptology Additional material September 27, 2005 1 Structure of Finite Fields This section contains complementary material to Section 5.2.3 of the text-book. It is not entirely self-contained
More information2 More on Congruences
2 More on Congruences 2.1 Fermat s Theorem and Euler s Theorem definition 2.1 Let m be a positive integer. A set S = {x 0,x 1,,x m 1 x i Z} is called a complete residue system if x i x j (mod m) whenever
More informationOn The Weights of Binary Irreducible Cyclic Codes
On The Weights of Binary Irreducible Cyclic Codes Yves Aubry and Philippe Langevin Université du Sud Toulon-Var, Laboratoire GRIM F-83270 La Garde, France, {langevin,yaubry}@univ-tln.fr, WWW home page:
More informationCHAPTER 6. Prime Numbers. Definition and Fundamental Results
CHAPTER 6 Prime Numbers Part VI of PJE. Definition and Fundamental Results 6.1. Definition. (PJE definition 23.1.1) An integer p is prime if p > 1 and the only positive divisors of p are 1 and p. If n
More informationOn the power-free parts of consecutive integers
ACTA ARITHMETICA XC4 (1999) On the power-free parts of consecutive integers by B M M de Weger (Krimpen aan den IJssel) and C E van de Woestijne (Leiden) 1 Introduction and main results Considering the
More informationElementary Number Theory Review. Franz Luef
Elementary Number Theory Review Principle of Induction Principle of Induction Suppose we have a sequence of mathematical statements P(1), P(2),... such that (a) P(1) is true. (b) If P(k) is true, then
More informationA talk given at University of Wisconsin at Madison (April 6, 2006). Zhi-Wei Sun
A tal given at University of Wisconsin at Madison April 6, 2006. RECENT PROGRESS ON CONGRUENCES INVOLVING BINOMIAL COEFFICIENTS Zhi-Wei Sun Department of Mathematics Nanjing University Nanjing 210093,
More informationSuper congruences involving binomial coefficients and new series for famous constants
Tal at the 5th Pacific Rim Conf. on Math. (Stanford Univ., 2010 Super congruences involving binomial coefficients and new series for famous constants Zhi-Wei Sun Nanjing University Nanjing 210093, P. R.
More informationApéry Numbers, Franel Numbers and Binary Quadratic Forms
A tal given at Tsinghua University (April 12, 2013) and Hong Kong University of Science and Technology (May 2, 2013) Apéry Numbers, Franel Numbers and Binary Quadratic Forms Zhi-Wei Sun Nanjing University
More informationMath 314 Course Notes: Brief description
Brief description These are notes for Math 34, an introductory course in elementary number theory Students are advised to go through all sections in detail and attempt all problems These notes will be
More informationMath 110 HW 3 solutions
Math 0 HW 3 solutions May 8, 203. For any positive real number r, prove that x r = O(e x ) as functions of x. Suppose r
More informationThe security of RSA (part 1) The security of RSA (part 1)
The modulus n and its totient value φ(n) are known φ(n) = p q (p + q) + 1 = n (p + q) + 1 The modulus n and its totient value φ(n) are known φ(n) = p q (p + q) + 1 = n (p + q) + 1 i.e. q = (n φ(n) + 1)
More informationMATH 4400 SOLUTIONS TO SOME EXERCISES. 1. Chapter 1
MATH 4400 SOLUTIONS TO SOME EXERCISES 1.1.3. If a b and b c show that a c. 1. Chapter 1 Solution: a b means that b = na and b c that c = mb. Substituting b = na gives c = (mn)a, that is, a c. 1.2.1. Find
More informationECEN 5022 Cryptography
Elementary Algebra and Number Theory University of Colorado Spring 2008 Divisibility, Primes Definition. N denotes the set {1, 2, 3,...} of natural numbers and Z denotes the set of integers {..., 2, 1,
More informationNumber Theory, Algebra and Analysis. William Yslas Vélez Department of Mathematics University of Arizona
Number Theory, Algebra and Analysis William Yslas Vélez Department of Mathematics University of Arizona O F denotes the ring of integers in the field F, it mimics Z in Q How do primes factor as you consider
More informationNONABELIAN GROUPS WITH PERFECT ORDER SUBSETS
NONABELIAN GROUPS WITH PERFECT ORDER SUBSETS CARRIE E. FINCH AND LENNY JONES Abstract. Let G be a finite group and let x G. Define the order subset of G determined by x to be the set of all elements in
More informationSelected Chapters from Number Theory and Algebra
Selected Chapters from Number Theory and Algebra A project under construction Franz Rothe Department of Mathematics University of North Carolina at Charlotte Charlotte, NC 83 frothe@uncc.edu December 8,
More informationFermat s Little Theorem. Fermat s little theorem is a statement about primes that nearly characterizes them.
Fermat s Little Theorem Fermat s little theorem is a statement about primes that nearly characterizes them. Theorem: Let p be prime and a be an integer that is not a multiple of p. Then a p 1 1 (mod p).
More informationPMA225 Practice Exam questions and solutions Victor P. Snaith
PMA225 Practice Exam questions and solutions 2005 Victor P. Snaith November 9, 2005 The duration of the PMA225 exam will be 2 HOURS. The rubric for the PMA225 exam will be: Answer any four questions. You
More informationChapter 9 Mathematics of Cryptography Part III: Primes and Related Congruence Equations
Chapter 9 Mathematics of Cryptography Part III: Primes and Related Congruence Equations Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 9.1 Chapter 9 Objectives
More informationThe Chinese Remainder Theorem
Chapter 5 The Chinese Remainder Theorem 5.1 Coprime moduli Theorem 5.1. Suppose m, n N, and gcd(m, n) = 1. Given any remainders r mod m and s mod n we can find N such that N r mod m and N s mod n. Moreover,
More informationLecture notes: Algorithms for integers, polynomials (Thorsten Theobald)
Lecture notes: Algorithms for integers, polynomials (Thorsten Theobald) 1 Euclid s Algorithm Euclid s Algorithm for computing the greatest common divisor belongs to the oldest known computing procedures
More informationON THE p-adic VALUE OF JACOBI SUMS OVER F p
Kyushu J. Math. 68 (014), 3 38 doi:10.06/kyushujm.68.3 ON THE p-adic VALUE OF JACOBI SUMS OVER F p 3 Takahiro NAKAGAWA (Received 9 November 01 and revised 3 April 014) Abstract. Let p be a prime and q
More informationApplied Cryptography and Computer Security CSE 664 Spring 2018
Applied Cryptography and Computer Security Lecture 12: Introduction to Number Theory II Department of Computer Science and Engineering University at Buffalo 1 Lecture Outline This time we ll finish the
More information10 Problem 1. The following assertions may be true or false, depending on the choice of the integers a, b 0. a "
Math 4161 Dr. Franz Rothe December 9, 2013 13FALL\4161_fall13f.tex Name: Use the back pages for extra space Final 70 70 Problem 1. The following assertions may be true or false, depending on the choice
More informationYALE UNIVERSITY DEPARTMENT OF COMPUTER SCIENCE
YALE UNIVERSITY DEPARTMENT OF COMPUTER SCIENCE CPSC 467a: Cryptography and Computer Security Notes 13 (rev. 2) Professor M. J. Fischer October 22, 2008 53 Chinese Remainder Theorem Lecture Notes 13 We
More informationPrimitive Roots and Discrete Logarithms
Primitive Roots and Discrete Logarithms L. Felipe Martins Department of Mathematics Cleveland State University l.martins@csuohio.edu Work licensed under a Creative Commons License available at http://creativecommons.org/licenses/by-nc-sa/3.0/us/
More informationMath 4400 First Midterm Examination September 21, 2012 ANSWER KEY. Please indicate your reasoning and show all work on this exam paper.
Name: Math 4400 First Midterm Examination September 21, 2012 ANSWER KEY Please indicate your reasoning and show all work on this exam paper. Relax and good luck! Problem Points Score 1 20 20 2 20 20 3
More information3 Solutions of congruences
3 Solutions of congruences 3.1 The Chinese Remainder Theorem revisited Let f(x) be a polynomial with coefficients in Z. A congruence equation is of the form f(x) 0 (mod m), where m is a positive integer.
More informationDiscrete Logarithms. Let s begin by recalling the definitions and a theorem. Let m be a given modulus. Then the finite set
Discrete Logarithms Let s begin by recalling the definitions and a theorem. Let m be a given modulus. Then the finite set Z/mZ = {[0], [1],..., [m 1]} = {0, 1,..., m 1} of residue classes modulo m is called
More informationA. Algebra and Number Theory
A. Algebra and Number Theory Public-key cryptosystems are based on modular arithmetic. In this section, we summarize the concepts and results from algebra and number theory which are necessary for an understanding
More informationThis is a recursive algorithm. The procedure is guaranteed to terminate, since the second argument decreases each time.
8 Modular Arithmetic We introduce an operator mod. Let d be a positive integer. For c a nonnegative integer, the value c mod d is the remainder when c is divided by d. For example, c mod d = 0 if and only
More informationThe critical group of a graph
The critical group of a graph Peter Sin Texas State U., San Marcos, March th, 4. Critical groups of graphs Outline Laplacian matrix of a graph Chip-firing game Smith normal form Some families of graphs
More informationCOMP239: Mathematics for Computer Science II. Prof. Chadi Assi EV7.635
COMP239: Mathematics for Computer Science II Prof. Chadi Assi assi@ciise.concordia.ca EV7.635 The Euclidean Algorithm The Euclidean Algorithm Finding the GCD of two numbers using prime factorization is
More informationKnow the Well-ordering principle: Any set of positive integers which has at least one element contains a smallest element.
The first exam will be on Monday, June 8, 202. The syllabus will be sections. and.2 in Lax, and the number theory handout found on the class web site, plus the handout on the method of successive squaring
More informationD-MATH Algebra II FS18 Prof. Marc Burger. Solution 26. Cyclotomic extensions.
D-MAH Algebra II FS18 Prof. Marc Burger Solution 26 Cyclotomic extensions. In the following, ϕ : Z 1 Z 0 is the Euler function ϕ(n = card ((Z/nZ. For each integer n 1, we consider the n-th cyclotomic polynomial
More informationPublic-key Cryptography: Theory and Practice
Public-key Cryptography Theory and Practice Department of Computer Science and Engineering Indian Institute of Technology Kharagpur Chapter 2: Mathematical Concepts Divisibility Congruence Quadratic Residues
More informationQ 2.0.2: If it s 5:30pm now, what time will it be in 4753 hours? Q 2.0.3: Today is Wednesday. What day of the week will it be in one year from today?
2 Mod math Modular arithmetic is the math you do when you talk about time on a clock. For example, if it s 9 o clock right now, then it ll be 1 o clock in 4 hours. Clearly, 9 + 4 1 in general. But on a
More informationMath 4400/6400 Homework #8 solutions. 1. Let P be an odd integer (not necessarily prime). Show that modulo 2,
MATH 4400 roblems. Math 4400/6400 Homework # solutions 1. Let P be an odd integer not necessarily rime. Show that modulo, { P 1 0 if P 1, 7 mod, 1 if P 3, mod. Proof. Suose that P 1 mod. Then we can write
More informationPart IA Numbers and Sets
Part IA Numbers and Sets Definitions Based on lectures by A. G. Thomason Notes taken by Dexter Chua Michaelmas 2014 These notes are not endorsed by the lecturers, and I have modified them (often significantly)
More informationLECTURE NOTES IN CRYPTOGRAPHY
1 LECTURE NOTES IN CRYPTOGRAPHY Thomas Johansson 2005/2006 c Thomas Johansson 2006 2 Chapter 1 Abstract algebra and Number theory Before we start the treatment of cryptography we need to review some basic
More information4 PRIMITIVE ROOTS Order and Primitive Roots The Index Existence of primitive roots for prime modulus...
PREFACE These notes have been prepared by Dr Mike Canfell (with minor changes and extensions by Dr Gerd Schmalz) for use by the external students in the unit PMTH 338 Number Theory. This booklet covers
More informationEXAMPLES OF MORDELL S EQUATION
EXAMPLES OF MORDELL S EQUATION KEITH CONRAD 1. Introduction The equation y 2 = x 3 +k, for k Z, is called Mordell s equation 1 on account of Mordell s long interest in it throughout his life. A natural
More informationChapter 8. Introduction to Number Theory
Chapter 8 Introduction to Number Theory CRYPTOGRAPHY AND NETWORK SECURITY 1 Index 1. Prime Numbers 2. Fermat`s and Euler`s Theorems 3. Testing for Primality 4. Discrete Logarithms 2 Prime Numbers 3 Prime
More informationIntegers and Division
Integers and Division Notations Z: set of integers N : set of natural numbers R: set of real numbers Z + : set of positive integers Some elements of number theory are needed in: Data structures, Random
More informationA connection between number theory and linear algebra
A connection between number theory and linear algebra Mark Steinberger Contents 1. Some basics 1 2. Rational canonical form 2 3. Prime factorization in F[x] 4 4. Units and order 5 5. Finite fields 7 6.
More informationALGEBRA I (LECTURE NOTES 2017/2018) LECTURE 9 - CYCLIC GROUPS AND EULER S FUNCTION
ALGEBRA I (LECTURE NOTES 2017/2018) LECTURE 9 - CYCLIC GROUPS AND EULER S FUNCTION PAVEL RŮŽIČKA 9.1. Congruence modulo n. Let us have a closer look at a particular example of a congruence relation on
More informationON THE SEMIPRIMITIVITY OF CYCLIC CODES
ON THE SEMIPRIMITIVITY OF CYCLIC CODES YVES AUBRY AND PHILIPPE LANGEVIN Abstract. We prove, without assuming the Generalized Riemann Hypothesis, but with at most one exception, that an irreducible cyclic
More informationExam 2 Solutions. In class questions
Math 5330 Spring 2018 Exam 2 Solutions In class questions 1. (15 points) Solve the following congruences. Put your answer in the form of a congruence. I usually find it easier to go from largest to smallest
More informationMA257: INTRODUCTION TO NUMBER THEORY LECTURE NOTES
MA257: INTRODUCTION TO NUMBER THEORY LECTURE NOTES 2018 57 5. p-adic Numbers 5.1. Motivating examples. We all know that 2 is irrational, so that 2 is not a square in the rational field Q, but that we can
More informationNumber Theory and Algebra: A Brief Introduction
Number Theory and Algebra: A Brief Introduction Indian Statistical Institute Kolkata May 15, 2017 Elementary Number Theory: Modular Arithmetic Definition Let n be a positive integer and a and b two integers.
More informationMATH 25 CLASS 12 NOTES, OCT Contents 1. Simultaneous linear congruences 1 2. Simultaneous linear congruences 2
MATH 25 CLASS 12 NOTES, OCT 17 2011 Contents 1. Simultaneous linear congruences 1 2. Simultaneous linear congruences 2 1. Simultaneous linear congruences There is a story (probably apocryphal) about how
More informationSOLUTIONS TO PROBLEM SET 1. Section = 2 3, 1. n n + 1. k(k + 1) k=1 k(k + 1) + 1 (n + 1)(n + 2) n + 2,
SOLUTIONS TO PROBLEM SET 1 Section 1.3 Exercise 4. We see that 1 1 2 = 1 2, 1 1 2 + 1 2 3 = 2 3, 1 1 2 + 1 2 3 + 1 3 4 = 3 4, and is reasonable to conjecture n k=1 We will prove this formula by induction.
More informationNumber Theory. Henry Liu, 6 July 2007
Number Theory Henry Liu, 6 July 007 1. Introduction In one sentence, number theory is the area of mathematics which studies the properties of integers. Some of the most studied subareas are the theories
More informationCYCLICITY OF (Z/(p))
CYCLICITY OF (Z/(p)) KEITH CONRAD 1. Introduction For each prime p, the group (Z/(p)) is cyclic. We will give seven proofs of this fundamental result. A common feature of the proofs that (Z/(p)) is cyclic
More informationNumber Theory and Group Theoryfor Public-Key Cryptography
Number Theory and Group Theory for Public-Key Cryptography TDA352, DIT250 Wissam Aoudi Chalmers University of Technology November 21, 2017 Wissam Aoudi Number Theory and Group Theoryfor Public-Key Cryptography
More informationCPSC 467: Cryptography and Computer Security
CPSC 467: Cryptography and Computer Security Michael J. Fischer Lecture 9 September 30, 2015 CPSC 467, Lecture 9 1/47 Fast Exponentiation Algorithms Number Theory Needed for RSA Elementary Number Theory
More informationCryptography. Number Theory with AN INTRODUCTION TO. James S. Kraft. Lawrence C. Washington. CRC Press
AN INTRODUCTION TO Number Theory with Cryptography James S Kraft Gilman School Baltimore, Maryland, USA Lawrence C Washington University of Maryland College Park, Maryland, USA CRC Press Taylor & Francis
More informationcongruences Shanghai, July 2013 Simple proofs of Ramanujan s partition congruences Michael D. Hirschhorn
s s m.hirschhorn@unsw.edu.au Let p(n) be the number of s of n. For example, p(4) = 5, since we can write 4 = 4 = 3+1 = 2+2 = 2+1+1 = 1+1+1+1 and there are 5 such representations. It was known to Euler
More informationDiscrete Mathematics and Probability Theory Fall 2014 Anant Sahai Homework 5. This homework is due October 6, 2014, at 12:00 noon.
EECS 70 Discrete Mathematics and Probability Theory Fall 2014 Anant Sahai Homework 5 This homework is due October 6, 2014, at 12:00 noon. 1. Modular Arithmetic Lab (continue) Oystein Ore described a puzzle
More informationWinter Camp 2009 Number Theory Tips and Tricks
Winter Camp 2009 Number Theory Tips and Tricks David Arthur darthur@gmail.com 1 Introduction This handout is about some of the key techniques for solving number theory problems, especially Diophantine
More informationElementary Properties of Cyclotomic Polynomials
Elementary Properties of Cyclotomic Polynomials Yimin Ge Abstract Elementary properties of cyclotomic polynomials is a topic that has become very popular in Olympiad mathematics. The purpose of this article
More informationRelations. Binary Relation. Let A and B be sets. A (binary) relation from A to B is a subset of A B. Notation. Let R A B be a relation from A to B.
Relations Binary Relation Let A and B be sets. A (binary) relation from A to B is a subset of A B. Notation Let R A B be a relation from A to B. If (a, b) R, we write a R b. 1 Binary Relation Example:
More information#A11 INTEGERS 12 (2012) FIBONACCI VARIATIONS OF A CONJECTURE OF POLIGNAC
#A11 INTEGERS 12 (2012) FIBONACCI VARIATIONS OF A CONJECTURE OF POLIGNAC Lenny Jones Department of Mathematics, Shippensburg University, Shippensburg, Pennsylvania lkjone@ship.edu Received: 9/17/10, Revised:
More informationLecture 5: Arithmetic Modulo m, Primes and Greatest Common Divisors Lecturer: Lale Özkahya
BBM 205 Discrete Mathematics Hacettepe University http://web.cs.hacettepe.edu.tr/ bbm205 Lecture 5: Arithmetic Modulo m, Primes and Greatest Common Divisors Lecturer: Lale Özkahya Resources: Kenneth Rosen,
More information