An estimate for the number of consecutive quadratic residues

The problem of estimation of the maximal number H of consecutive integer numbers such that they all are either quadratic residues or quadratic nonresidues modulo a prime number p is considered.     

Consecutive residues and nonresidues of polynomials

The author examines the distribution of common residues (mod p) of any polynomialsf ₁(x) andf ₂(x) and the distribution of consecutive residues and nonresidues of any degree.Translated from Matematicheskie Zametki, Vol. 7, No. 1, pp. 97–107, January, 1970.     

On Cyclotomic Numbers and the Reduction Map for the K-Theory of the Integers

We apply the recently proven compatibility of Beilinson and Soulé elements in K-theory to investigate density of rational primes p, for which the reduction map K _2n+1() K_{2n+1}(F_p)is nontrivial. Here n is an even, positive integer and F_p denotes the field of p elements. In the proof we use arithmetic of cyclotomic numbers which come from Soulé elements. Divisibility properties of the numbers are related to the Vandiver conjecture on the class group of cyclotomic fields. Using the K-theory of the integers, we compute an upper bound on the divisibility of these cyclotomic numbers.     

The distribution of quadratic residues and nonresidues in arithmetic progressions

We prove some results concerning the distribution of quadratic residues and nonresidues in arithmetic progressions in the setting \( {{\mathbb{F}}_p}={{\mathbb{Z}} \left/ {{p\mathbb{Z}}} \right.} \) , where p is a large prime.     

Patterns of quadratic residues and nonresidues for infinitely many primes

If S is a nonempty, finite subset of the positive integers, we address the question of when the elements of S consist of various mixtures of quadratic residues and nonresidues for infinitely many primes. We are concerned in particular with the problem of characterizing those subsets of integers that consist entirely of either (1) quadratic residues or (2) quadratic nonresidues for such a set of primes. We solve problem (1) and we show that problem (2) is equivalent to a purely combinatorial problem concerning families of subsets of a finite set. For sets S of (essentially) small cardinality, we solve problem (2). Related results and some associated enumerative combinatorics are also discussed.     

Concentration of Points on Two and Three Dimensional Modular Hyperbolas and Applications

Let p be a large prime number, K, L, M, λ be integers with 1 ≤ M ≤ p and gcd(λ, p) = 1. The aim of our paper is to obtain sharp upper bound estimates for the number I ₂(M; K, L) of solutions of the congruence

On a Problem of Fabrykowski and Subbarao Concerning Quasi Multiplicative Functions Satisfying a Congruence Property

It follows from our result that if a quasi multiplicative function f satisfies the congruence f(n + p) f(n) (mod p) for all positive integers n and for all sufficiently large primes p, then there is a non-negative integer such that f(n) = n holds for all positive integers n. In particular, this gives an answer to the conjecture of Fabrykowski and Subbarao.     

Class number one quadratic fields and solvability of some Pellian equations

Consider these two types of positive square-free integers d≠ 1 for which the class number h of the quadratic field Q(√d) is odd: (1) d is prime∈ 1(mod 8), or d=2q where q is prime ≡ 3 (mod 4), or d=qr where q and r are primes such that q≡ 3 (mod 8) and r≡ 7 (mod 8); (2) d is prime ≡ 1 (mod 8), or d=qr where q and r are primes such that q≡r≡ 3 or 7 (mod 8). For d of type (2) (resp. (1)), let Π be the set of all primes (resp. odd primes) p∈N satisfying (d/p) = 1. Also, let δ :=0 (resp. δ :=1) if d≡ 2,3 (mod 4) (resp. d≡ 1 (mod 4)). Then the following are equivalent: (a) h=1; (b) For every p∈П at least one of the two Pellian equations Z ²-dY ² = ±4^δ p is solvable in integers. (c) For every p∈П the Pellian equation W ²-dV ² = 4^δ p ² has a solution (w,v) in integers such that gcd (w,v) divides 2^δ.     

On thel-connectivity of a graph

For an integerl 2, thel-connectivity of a graphG is the minimum number of vertices whose removal fromG produces a disconnected graph with at leastl components or a graph with fewer thanl vertices. A graphG is (n, l)-connected if itsl-connectivity is at leastn. Several sufficient conditions for a graph to be (n, l)-connected are established. IfS is a set ofl( 3) vertices of a graphG, then anS-path ofG is a path between distinct vertices ofS that contains no other vertices ofS. TwoS-paths are said to be internally disjoint if they have no vertices in common, except possibly end-vertices. For a given setS ofl 2 vertices of a graphG, a sufficient condition forG to contain at leastn internally disjointS-paths, each of length at most 2, is established.     

Further progress on difference families with block size 4 or 5

A strong indication about the existence of a (7p, 4, 1) difference family with p ≡ 7 (mod 12) a prime has been given in [11]. Here, developing some ideas of that paper, we give, much more generally, a strong indication about the existence of a cyclic (pq, 4, 1) difference family whenever p and q are primes congruent to 7 (mod 12) and of a cyclic (pq, 5, 1) difference family whenever p and q are primes congruent to 11 (mod 20). Indeed we give an algorithm for their construction that seems to be always successful and we have checked it works whenever both primes p and q do not exceed 1,000. All our (pq, 4, 1) and (pq, 5, 1) difference families have the nice property of admitting a multiplier of order 3 or 5, respectively, that fixes almost all base blocks. As an intermediate result we also find an optimal (p, 5, 1) optical orthogonal code for every prime p ≡ 11 (mod 20) not exceeding 10,000.     

A note on prime k-th power nonresidues

Bounds for the second and third smallestprime k-th power nonresidues of odd primes p have been given by Alfred Brauer, Clifton Whyburn, and L. K. Hua. Bounds for the n-th prime residue, n≥4, do not appear in the literature and it would be difficult to obtain bounds as sharp as p^1/4 if n is large and k is small. In this note we use the character sum estimates of D. A. Burgess to show that there are on the order of log p/log log pprime k-th power nonresidues less than p^{1/4 +∈} for every ∈>0 and sufficiently large p.     

The conductor of a cyclic quartic field using Gauss sums

Let Q denote the field of rational numbers. Let K be a cyclic quartic extension of Q. It is known that there are unique integers A, B, C, D such that where A is squarefree and odd, D=B ²+C ² is squarefree, B $$ " align="middle" border="0"> 0 , C $$ " align="middle" border="0"> 0, GCD(A,D)=1. The conductor f(K) of K is f(K) = 2 ^l |A|D, where A simple proof of this formula for f(K) is given, which uses the basic properties of quartic Gauss sums.     

On real quadratic function fields

Let q be a power of an odd prime number p and K:=Fq(T) be the rational function field with a fixed indeterminate T. For P a prime of K, let be the maximal real subfield of the Pth-cyclotomic function field and its ring of integers. We prove that there exists infinitely many primes P of even degree such that the cardinal of the ideal class group is divisible by q. We prove also an analogous result for imaginary extensions.     

Lower bounds of Ramsey numbers based on cubic residues

A method to improve the lower bounds for Ramsey numbers R(k,l) is provided: one may construct cyclic graphs by using cubic residues modulo the primes in the form p=6m+1 to produce desired examples. In particular, we obtain 16 new lower bounds, which are

R(6,12)230, R(5,15)242, R(6,14)284, R(6,15)374,R(6,16)434, R(6,17)548, R(6,18)614, R(6,19)710,R(6,20)878, R(6,21)884, R(7,19)908, R(6,22)1070,R(8,20)1094, R(7,21)1214, R(9,20)1304, R(8,21)1328.

     

On a Criterion for Catalan's Conjecture

We give a new proof of a theorem of P. Mihailescu which states that the equation x ^p – y ^q = 1 is unsolvable with x, y integral and p, q odd primes, unless the congruences p ^q p (mod q ²) and q ^p q (mod p ²) hold.     

A representation theorem and Z-cyclic whist tournaments

Let E denote the group of units (i.e., the reduce set of residues) in the ring Z. Here we consider q,p to be primes, q ≡ 3 (mod 4), q ? 7, p ≡ 1 (mod 4). Let W denote a common primitive root of 3, q, and p². If H denotes the (normal) subgroup of E that is generated by {?1, W}, we show that the factor group E/H is cyclic by demonstrating the existence of an element x in E such that the coset xH has order equal to |E/H|. This order is given by gcd(p^n?1(p ? 1),q ? 1). This representation of E/H is exploited via an appropriate construction to produce Z-cyclic whist tournaments for 3qpⁿ players. Consequently these results extend those of an early study of Wh(3qpⁿ) that was restricted to gcd(p^n?1(p ? 1),q ? 1) = 2. © 1995 John Wiley & Sons, Inc.     

On 3-pushdown graphs with large separators

For an integers letl ^s (n), thes-iterated logarithm function, be defined inductively:l ⁰ (n)=n,l ^s+1 (n)=log₂ (l ² (n)) fors0. We show that for every fixeds and alln large enough, there is ann-vertex 3-pushdown graph whose smallest separator contains at least(n/l ^s (n)) vertices.The work of the first author was supported in part by NSF Grants MCS-83-03139, DCR-85-11713 and CCR-86-05353.The work of the second author was supported in part by NSF Grants MCS-84-16190.     

Summability Kernels for <Emphasis Type="Italic">L</Emphasis><Superscript><Emphasis Type="Italic">p</Emphasis></Superscript> Multipliers

In this article we study the problem of extending Fourier Multipliers on L ^p (T) to those on L ^p (R) by taking convolution with a kernel, called a summability kernel. We characterize the space of such kernels for the cases p = 1 and p = 2. For other values of p we give a necessary condition for a function to be a summability kernel. For the case p = 1, we present properties of measures which are transferred from M(T) to M(R) by summability kernels. Furthermore it is shown that every l _p sequence can be extended to some L ^q (R) multipliers for certain values of p and q.     

On the primes withp n+1 -p n = 8 and the Sum of their Reciprocals

We introduce the counting function π _2,8 ^* (x) of the primes with difference 8 between consecutive primes ( ****p _n,p_n+1 =p _n + 8) can be approximated by logarithm integralLi _2,8 ^* . We calculate the values of π _2,8 ^* (x) and the sumC _2,8(x) of reciprocals of primes with difference 8 between consecutive primes (p _n,p_n+1 =p _n +8)) wherex is counted up to 7 x 10¹⁰. From the results of these calculations, we obtain π _2,8 ^* (7 x 10¹⁰) = 133295081 andC _2,8(7 x 10¹⁰) = 0.3374 ±2.6 x 10^-4.