A probabilistic solution for the Syracuse conjecture

We prove the veracity of the Syracuse conjecture by establishingthat starting from an arbitrary positive integer diffrent of 1 and 4, theSyracuse process will never comeback to any positive integer reachedbefore and then we conclude by using a probabilistic approach.Classification : MSC: 11A25

A probabilistic solution for the Syracuse conjecture

We prove the veracity of the Syracuse conjecture by establishing that starting from an arbitrary positive integer, the Syracuse process will never reach any integer reached before and then we conclude by using a probabilistic (a random walk) approach.Classification: MSC: 11A25

Logarithmic diameter bounds for some Cayley graphs

Let S ⊂ GL n ⁢ ( Z ) S\subset\mathrm{GL}_{n}(\mathbb{Z}) be a finite symmetric set. We show that if the Zariski closure of Γ = ⟨ S ⟩ \Gamma=\langle S\rangle is a product of special linear groups or a special affine linear group, then the diameter of the Cayley graph Cay ⁡ ( Γ / Γ ⁢ ( q ) , π q ⁢ ( S ) ) \operatorname{Cay}(\Gamma/\Gamma(q),\pi_{q}(S)) is O ⁢ ( log ⁡ q ) O(\log q) , where 𝑞 is an arbitrary positive integer, π q : Γ → Γ / Γ ⁢ ( q ) \pi_{q}\colon\Gamma\to\Gamma/\Gamma(q) is the canonical projection induced by the reduction modulo 𝑞, and the implied constant depends only on 𝑆.

Hit problem for the polynomial algebra as a module over the Steenrod algebra in some degrees

Let [Formula: see text] be the polynomial algebra in [Formula: see text] variables with the degree of each [Formula: see text] being [Formula: see text] regarded as a module over the mod-[Formula: see text] Steenrod algebra [Formula: see text] and let [Formula: see text] be the general linear group over the prime field [Formula: see text] which acts naturally on [Formula: see text]. We study the hit problem, set up by Frank Peterson, of finding a minimal set of generators for the polynomial algebra [Formula: see text] as a module over the mod-2 Steenrod algebra, [Formula: see text]. These results are used to study the Singer algebraic transfer which is a homomorphism from the homology of the mod-[Formula: see text] Steenrod algebra, [Formula: see text] to the subspace of [Formula: see text] consisting of all the [Formula: see text]-invariant classes of degree [Formula: see text] In this paper, we explicitly compute the hit problem for [Formula: see text] and the degree [Formula: see text] with [Formula: see text] an arbitrary positive integer. Using this result, we show that Singer’s conjecture for the algebraic transfer is true in the case [Formula: see text] and the above degree.

$\mathscr A$-generators for the polynomial algebra of five variables in degree $5(2^t - 1) + 6.2^t$

Let $P_s:= \mathbb{F}_2[x_1,x_2,\ldots ,x_s] = \bigoplus_{n\geqslant 0}(P_s)_n$ be the polynomial algebra viewedas a graded left module over the mod 2 Steenrod algebra, $\mathscr A.$ The grading is by the degree of the homogeneous terms $(P_s)_n$ of degree $n$ in the variables $x_1, x_2, \ldots, x_s$ of grading $1.$ We are interested in the {\it hit problem}, set up by F.P. Peterson, of finding a minimal system of generators for $\mathscr A$-module $P_s.$ Equivalently, we want to find a basis for the $\mathbb F_2$-graded vector space $\mathbb F_2\otimes_{\mathscr A} P_s.$ In this paper, we study the hit problem in the case $s=5$ and the degree $n = 5(2^t-1) + 6.2^t$ with $t$ an arbitrary positive integer.

Pseudo-free families of computational universal algebras

Let Ω be a finite set of finitary operation symbols. We initiate the study of (weakly) pseudo-free families of computational Ω-algebras in arbitrary varieties of Ω-algebras. A family (Hd | d ∈ D) of computational Ω-algebras (where D ⊆ {0, 1}*) is called polynomially bounded (resp., having exponential size) if there exists a polynomial η such that for all d ∈ D, the length of any representation of every h ∈ Hd is at most $\eta (|d|)\left( \text{ resp}\text{., }\left| {{H}_{d}} \right|\le {{2}^{\eta (|d|)}} \right).$ First, we prove the following trichotomy: (i) if Ω consists of nullary operation symbols only, then there exists a polynomially bounded pseudo-free family; (ii) if Ω = Ω0 ∪ {ω}, where Ω0 consists of nullary operation symbols and the arity of ω is 1, then there exist an exponential-size pseudo-free family and a polynomially bounded weakly pseudo-free family; (iii) in all other cases, the existence of polynomially bounded weakly pseudo-free families implies the existence of collision-resistant families of hash functions. In this trichotomy, (weak) pseudo-freeness is meant in the variety of all Ω-algebras. Second, assuming the existence of collision-resistant families of hash functions, we construct a polynomially bounded weakly pseudo-free family and an exponential-size pseudo-free family in the variety of all m-ary groupoids, where m is an arbitrary positive integer.

On decay rates of the solutions of parabolic Cauchy problems

We consider the Cauchy problem for a general class of parabolic partial differential equations in the Euclidean space ℝ N . We show that given a weighted L p -space $L_w^p({\mathbb {R}}^N)$ with 1 ⩽ p < ∞ and a fast growing weight w, there is a Schauder basis $(e_n)_{n=1}^\infty$ in $L_w^p({\mathbb {R}}^N)$ with the following property: given an arbitrary positive integer m there exists n m > 0 such that, if the initial data f belongs to the closed linear span of e n with n ⩾ n m , then the decay rate of the solution of the problem is at least t−m for large times t. The result generalizes the recent study of the authors concerning the classical linear heat equation. We present variants of the result having different methods of proofs and also consider finite polynomial decay rates instead of unlimited m.

Some Addition Formulas for Fibonacci, Pell and Jacobsthal Numbers

In this paper, we obtain a closed form for ${F_{\sum\nolimits_{i = 1}^k {} }}$, ${P_{\sum\nolimits_{i = 1}^k {} }}$and ${J_{\sum\nolimits_{i = 1}^k {} }}$ for some positive integers k where Fr, Pr and Jr are the rth Fibonacci, Pell and Jacobsthal numbers, respectively. We also give three open problems for the general cases ${F_{\sum\nolimits_{i = 1}^n {} }}$, ${P_{\sum\nolimits_{i = 1}^n {} }}$ and ${J_{\sum\nolimits_{i = 1}^n {} }}$for any arbitrary positive integer n.

Congruence properties of pk(n)

We present a unified approach to establish infinite families of congruences for [Formula: see text] for arbitrary positive integer [Formula: see text], where [Formula: see text] is given by the [Formula: see text]th power of the Euler product [Formula: see text]. For [Formula: see text], define [Formula: see text] to be the least positive integer such that [Formula: see text] and [Formula: see text] the least non-negative integer satisfying [Formula: see text]. Using the Atkin [Formula: see text]-operator, we find that the generating function of [Formula: see text] (respectively, [Formula: see text]) can be expressed as the product of an integral linear combination of modular functions on [Formula: see text] and [Formula: see text] (respectively, [Formula: see text]) for any [Formula: see text] and [Formula: see text]. By investigating the properties of the modular equations of the [Formula: see text]th order under the Atkin [Formula: see text]-operator, we obtain that these generating functions are determined by some linear recurring sequences. Utilizing the periodicity of these linear recurring sequences modulo [Formula: see text], we are led to infinite families of congruences for [Formula: see text] modulo any [Formula: see text] with [Formula: see text] and periodic relations between the values of [Formula: see text] modulo powers of [Formula: see text]. As applications, infinite families of congruences for many partition functions such as [Formula: see text]-core partition functions, the partition function and Andrews’ spt-function are easily obtained.