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1.
For the Diophantine equation
x^4 — Dy^2 = 1 (1)
where D>0 and is not a perfect square, we prove the following theorems in this paper.
Theorem 1. If D\[{\not \equiv }\]7 (mod 8),D=p1p2...ps,s≥2,where pi(i = 1,…,s) are distincyt primes,p1≡1(mod 4) such that either 2p1=a^2+b^2,а≡\[ \pm \]3(mod 8),b三\[ \pm \]3(mod 8) or there is a j(2≤j≤s), for which Legendre
symbal \[\left( {\frac{{{p_j}}}{{{p_1}}}} \right) = - 1\],and pi≡7(mod8) (i=2,..., s) or pi≡3(mod 8) (i=2,..., s), then (1) has no solutions in positive integer x,y.
Theorem 2. If D=p1...ps,s≥2, where pi(i = 1,…,s) are distinct primes, and pi≡3(mod 4)(i = 1,…,s), then (1) has no solutions in positive integer x, y.
Theorem 3. The equation (1) with D=2p1...ps has no solutions in positive
integer x, y, if
(1) p1≡(mod 4), pi≡7(mod 8) (i = 2, ???, s), snch that either 2p1 = a^2+b^2
a≡\[ \pm \]3(mod 8),b≡\[ \pm \]3(mod 8)or there is a j (2≤j≤s),for which \[\left( {\frac{{{p_j}}}{{{p_1}}}} \right) = - 1\];
or
(2) p1≡5(mod8),pi≡3(mod8) (i = 2,..., s);
or
⑶p1≡5(mod8),pi≡7(mod 8) (i=2,…,s).
Corollary of theorem 3. If D = 2pq, p≡5(mod 8), q≡3(mod 4), where p, q
are distinct primes, then (1) has no solutions in positive integer x, y.
Theorem 4. If D=2p1...ps, pi≡3(mod 4)(0 = 1,...,s), then (1) has no solutions In positive integer x, y. 相似文献
2.
Chun Lai ZHAO 《数学学报(英文版)》2005,21(5):961-976
Let D = p1p2 …pm, where p1,p2, ……,pm are distinct rational primes with p1 ≡p2 ≡3(mod 8), pi =1(mod 8)(3 ≤ i ≤ m), and m is any positive integer. In this paper, we give a simple combinatorial criterion for the value of the complex L-function of the congruent elliptic curve ED2 : y^2 = x^3- D^2x at s = 1, divided by the period ω defined below, to be exactly divisible by 2^2m-2, the second lowest 2-power with respect to the number of the Gaussian prime factors of D. As a corollary, we obtain a new series of non-congruent numbers whose prime factors can be arbitrarily many. Our result is in accord with the predictions of the conjecture of Birch and Swinnerton-Dyer. 相似文献
3.
《中国科学 数学(英文版)》2015,(7)
Suppose F = Q(√-p1 pt) is an imaginary quadratic number field with distinct primes p1,..., pt,where pi≡ 1(mod 4)(i = 1,..., t- 1) and pt ≡ 3(mod 4). We express the possible values of the 8-rank r8 of the class group of F in terms of a quadratic form Q over F2 which is defined by quartic symbols. In particular,we show that r8 is bounded by the isotropy index of Q. 相似文献
4.
《数学学报》2005,(6)
<正>Let D=P1 P2…Pm, where P1, P2,…, Pm are distinct rational primes with P1≡P2≡3(mod 8), Pi≡1(mod 8)(3≤i≤m), and m is any positive integer. In this paper, we give a simple combinatorial criterion for the value of the complex L-function of the congruent elliptic curve E_(D~2): y~2=x~3-D~2 x at s=1, divided by the period w defined below, to be exactly divisible by 2~(2m-2), the second lowest 2-power with respect to the number of the Gaussian prime factors of D. As a corollary, we obtain a new series of non-congruent numbers whose prime factors can be arbitrarily many. Our result is in accord with the predictions of the conjecture of Birch and Swinnerton-Dyer. 相似文献
5.
Aleksander GRYTCZUK Jarostaw GRYTCZUK 《数学学报(英文版)》2005,21(5):1107-1112
We investigate arithmetic properties of certain subsets of square-free positive integers and obtain in this way some results concerning the class number h(d) of the real quadratic field Q(√d). In particular, we give a new proof of the result of Hasse, asserting that in this case h(d) = 1 is possible only if d is of the form p, 2q or qr. where p.q. r are primes and q≡r≡3(mod 4). 相似文献
6.
《高校应用数学学报(英文版)》2010,(4)
Let Γ be a finite simple undirected graph with no isolated vertices. Let p, q be prime numbers with p ≥ q. We complete the classification of the graphs on which a group of order pq acts edge-transitively. The results are the following. If Aut(Γ) contains a subgroup G of order pq that acts edge-transitively on Γ, then Γ is one of the following graphs: (1) pK 1,1 ; (2) pqK 1,1 ; (3) pK q,1 ; (4) qK p,1 (p q); (5) pC q (q 2); (6) qC p (p q); (7) C p (p q = 2); (8) C pq ; (9) (Z p , C) where C = {±rμ | μ∈ Z q } with q 2, q|(p-1) and r ≡ 1 ≡ r q (mod p); (10) K p,1 (p q); (11) a double Cayley graph B(G, C) with C = {1-r μ | μ∈ Z q } and r ≡ 1 ≡ r q (mod p); (12) K pq,1 ; or (13) K p,q . 相似文献
7.
SUN Zhi-Wei 《中国科学 数学(英文版)》2014,57(7):1375-1400
For integers b and c the generalized central trinomial coefficient Tn(b,c)denotes the coefficient of xnin the expansion of(x2+bx+c)n.Those Tn=Tn(1,1)(n=0,1,2,...)are the usual central trinomial coefficients,and Tn(3,2)coincides with the Delannoy number Dn=n k=0n k n+k k in combinatorics.We investigate congruences involving generalized central trinomial coefficients systematically.Here are some typical results:For each n=1,2,3,...,we have n-1k=0(2k+1)Tk(b,c)2(b2-4c)n-1-k≡0(mod n2)and in particular n2|n-1k=0(2k+1)D2k;if p is an odd prime then p-1k=0T2k≡-1p(mod p)and p-1k=0D2k≡2p(mod p),where(-)denotes the Legendre symbol.We also raise several conjectures some of which involve parameters in the representations of primes by certain binary quadratic forms. 相似文献
8.
ChunGang Ji 《中国科学 数学(英文版)》2010,53(9):2269-2274
Let A(n) be the largest absolute value of any coefficient of n-th cyclotomic polynomial Φn(x).We say Φn(x) is flat if A(n) = 1.In this paper,for odd primes p q r and 2r ≡ 1(mod pq),we prove that Φpqr(x) is flat if and only if p = 3 and q ≡ 1(mod 3). 相似文献
9.
We consider the numberπ(x,y;q,a)of primes p≤such that p≡a(mod q)and(p-a)/q is free of prime factors greater than y.Assuming a suitable form of Elliott-Halberstam conjecture,it is proved thatπ(x,y:q,a)is asymptotic to p(log(x/q)/log y)π(x)/φ(q)on average,subject to certain ranges of y and q,where p is the Dickman function.Moreover,unconditional upper bounds are also obtained via sieve methods.As a typical application,we may control more effectively the number of shifted primes with large prime factors. 相似文献
10.
Let E = Eσ : y2 = x(x + σp)(x + σq) be elliptic curves, where σ = ±1, p and q are primenumbers with p+2 = q. (i) Selmer groups S(2)(E/Q), S(φ)(E/Q), and S(φ)(E/Q) are explicitly determined,e.g. S(2)(E+1/Q)= (Z/2Z)2, (Z/2Z)3, and (Z/2Z)4 when p ≡ 5, 1 (or 3), and 7(mod 8), respectively. (ii)When p ≡ 5 (3, 5 for σ = -1) (mod 8), it is proved that the Mordell-Weil group E(Q) ≌ Z/2Z Z/2Z,symbol, the torsion subgroup E(K)tors for any number field K, etc. are also obtained. 相似文献
11.
WEI DaSheng 《中国科学 数学(英文版)》2014,57(1):49-60
We determine the sum of two integral squares over imaginary quadratic fields Q(√-2p),where p≡1 mod 8 is a prime satisfying 2p=r2+s2with r,s≡±3 mod 8. 相似文献
12.
WEI DaSheng 《中国科学 数学(英文版)》2014,(1)
We determine the sum of two integral squares over imaginary quadratic fields Q(√-2p),where p≡1 mod 8 is a prime satisfying 2p=r2+s2with r,s≡±3 mod 8. 相似文献
13.
OD-CHARACTERIZATION OF ALMOST SIMPLE GROUPS RELATED TO U6(2) 总被引:1,自引:0,他引:1
Let G be a finite group and π(G) = { p 1 , p 2 , ··· , p k } be the set of the primes dividing the order of G. We define its prime graph Γ(G) as follows. The vertex set of this graph is π(G), and two distinct vertices p, q are joined by an edge if and only if pq ∈π e (G). In this case, we write p ~ q. For p ∈π(G), put deg(p) := |{ q ∈π(G) | p ~ q }| , which is called the degree of p. We also define D(G) := (deg(p 1 ), deg(p 2 ), ··· , deg(p k )), where p 1 < p 2 < ··· < p k , which is called the degree pattern of G. We say a group G is k-fold OD-characterizable if there exist exactly k non-isomorphic finite groups with the same order and degree pattern as G. Specially, a 1-fold OD-characterizable group is simply called an OD-characterizable group. Let L := U 6 (2). In this article, we classify all finite groups with the same order and degree pattern as an almost simple groups related to L. In fact, we prove that L and L.2 are OD-characterizable, L.3 is 3-fold OD-characterizable, and L.S 3 is 5-fold OD-characterizable. 相似文献
14.
Let n = p1p2 ··· pk, where pi(1 ≤ i ≤ k) are primes in the descending order and are not all equal. Let Ωk(n) = P(p1 + p2)P(p2 + p3) ··· P(pk-1+ pk)P(pk+ p1), where P(n) is the largest prime factor of n. Define w0(n) = n and wi(n) = w(wi-1(n)) for all integers i ≥ 1. The smallest integer s for which there exists a positive integer t such thatΩs k(n) = Ωs+t k(n) is called the index of periodicity of n. The authors investigate the index of periodicity of n. 相似文献
15.
Let p,q be distinct primes with gcd(p-1,q-1) = 4.In this paper,we calculate the autocorrelation values of binary sequences of generalized cyclotomic sets of order four in Z pq and get conditions of p and q such that they are four-valued. 相似文献
16.
For a graph G,let D denote an orientation of G having minimum diameter. Define f(G)=diamD.In this paper,we concentrate on exploring the minimum diameter of K_m∨(m≥1,n≥1).Some special cases are known:f(K_m∨)=∞,2,3, where m=1 and n≥1,m=2 or m≥4 and n=1,m=3 and n=1,respectively. So we only consider the case when m≥2 and n≥2.The following results are obtained. (1) f(K_m∨)=3,where m=2,3,n≥2 and m=n=4.(2) f(K_m∨)=2, where m≥5 and m is odd,2≤n≤■-m.(3) f(K_m∨)=2,where m≥4 and m≡0(mod4),2≤n≤■-(m/2 1).(4) f(K_m∨)=2,where m≥6 and m≡2(mod4),2≤n≤■-m/2.(5) f(K_m∨)=3,where m≥4,n>■. 相似文献
17.
Xi Mei WU Qin YUE 《数学学报(英文版)》2007,23(11):2061-2068
Let F = Q(√-p1p2) be an imaginary quadratic field with distinct primes p1 = p2 = 1 mod 8 and the Legendre symbol (p1/p2) = 1. Then the 8-rank of the class group of F is equal to 2 if and only Pl if the following conditions hold: (1) The quartic residue symbols (p1/p2)4 = (p2/p1)4 = 1; (2) Either both
p1 and p2 are represented by the form a^2 + 32b^2 over Z and p^h2+(2p1)/4=x^2-2p1y^2,x,y∈Z,or both p1 and p2 are not represented by the form a^2 + 32b^2 over Z and p^h2+(2p1)/4=ε(2x^2-p1y^2),x,y∈Z,ε∈{±1},where h+(2p1) is the narrow class number of Q(√2p1),Moreover, we also generalize these results. 相似文献
18.
ZhiWei Sun 《中国科学 数学(英文版)》2010,53(9):2473-2488
Let p be an odd prime and let a,m ∈ Z with a 0 and p ︱ m.In this paper we determinep ∑k=0 pa-1(2k k=d)/mk mod p2 for d=0,1;for example,where(-) is the Jacobi symbol and {un}n≥0 is the Lucas sequence given by u0 = 0,u1 = 1 and un+1 =(m-2)un-un-1(n = 1,2,3,...).As an application,we determine ∑0kpa,k≡r(mod p-1) Ck modulo p2 for any integer r,where Ck denotes the Catalan number 2kk /(k + 1).We also pose some related conjectures. 相似文献
19.
If q is an odd integer, q≥3,for any integers α, (α,q) = 1,there exsits a positiveinteger α, so tbat αα≡1(mod q) and 1≤α≤q - 1. Let L(q) = {α|α∈Z,1≤α≤q - 1, (α,q) = 1 and α +α=1(mod 2)}. (1)About the property of elements of L(q) is a generalization of a problem of D. H.Lenmer ([1],p. 12). In [3], it was conjectured that 相似文献
20.
LU Guangshi 《数学年刊B辑(英文版)》2005,26(2):291-304
It is proved that each sufficiently large integer N=5(mod24) can be written as N=p1^2+p2^2+p3^2+p4^2+p5^2 with|pj=√N/5|±、≤U=N^1/2-1/35+e,where pj ae primes.This result,which is obtained by an iterative method and a hybrid estimate for Dirichlet polynomial, improves the previous results in this direction. 相似文献