How many prime numbers are there? How are they distributed among other numbers? These are questions that have intrigued mathematicians since ancient times. However, many questions in this area have remained unsolved, and seemingly unsolvable in the forseeable future. In this snapshot, we will discuss one such problem, the Twin Prime Conjecture, and a quantitative version of it known as the Hard...

We prove the following conjecture of Narayana: there are no nontrivial dominance reene-ments of the Smirnov two-sample test if and only if the two sample sizes are relatively prime. We also count the number of natural signiicance levels of the Smirnov two-sample test in terms of the sample sizes and relate this to the Narayana conjecture. In particular, Smirnov tests with relatively prime sampl...

A graph is diameter two edge-critical if its diameter is two and the deletion of any edge increases the diameter. Murty and Simon conjectured that the number of edges in a diameter two edge-critical graph on n vertices is at most ⌊ n2 4 ⌋ and the extremal graph is the complete bipartite graph Kb 2 c,d 2 e. In the series papers [8–10], the Murty-Simon Conjecture stated by Haynes et al. is not th...

Let G = (V,E) be a simple graph. A subset Dof V (G) is a (k, r)dominating set if for every vertexv ∈ V −D, there exists at least k vertices in D which are at a distance utmost r from v in [1]. The minimum cardinality of a (k, r)-dominating set of G is called the (k, r)-domination number of G and is denoted by γ(k,r)(G). In this paper, minimal (k, r)dominating sets are characterized. It is prove...

The Prime Power Conjecture (PPC) states that abelian planar difference sets of order n exist only for n a prime power. Evans and Mann [1] verified this for cyclic difference sets for n ≤ 1600. In this paper we use the Mann test to verify the PPC for n ≤ 2, 000, 000.

For k > 1, r 6= 0 and large x, let π 2r (x) denote the number of prime pairs (p, p+2r) with p ≤ x. By the Bateman–Horn conjecture the function π 2r(x) should be asymptotic to (2/k)C k 2rli2(x), with certain specific constants C 2r . Heuristic arguments lead to the conjecture that these constants have mean value one, just like the Hardy–Littlewood constants C2r for prime pairs (p, p + 2r). The c...

In this paper we prove a special case of the transversal conjecture of Tverberg and Vrećica. We consider the case when the numbers of parts ri in this conjecture are powers of the same prime. We also prove some results on common transversals that generalize the classical nonembeddability theorems. We also prove an analogue of colored Tverberg’s theorem by Živaljević and Vrećica. Instead of mult...

The commuting graph of a group G, denoted by Γ(G), is the simple undirected graph whose vertices are the non-central elements of G and two distinct vertices are adjacent if and only if they commute. Let Zm be the commutative ring of equivalence classes of integers modulo m. In this paper we investigate the connectivity and diameters of the commuting graphs of GL(n,Zm) to contribute to the conje...

The Twin Prime Conjecture is a difficult unsolved problem in number theory; it states that there are infinitely many primes p such that p+2 is also prime. This is a special case of a more general statement known as Dickson’s Conjecture, which is that if h1, h2, . . . , hk are distinct integers satisfying some obviously necessary conditons, then there are infinitely many natural numbers n such that