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Ruslan Sharipov

Publications and source records attributed to Ruslan Sharipov.

At least 55 records · Page 3Linked to original sources
arXiv2012

A note on the second cuboid conjecture. Part I

The problem of finding perfect Euler cuboids or proving their non-existence is an old unsolved problem in mathematics. The second cuboid conjecture is one of the three propositions suggested as intermediate stages in proving the non-existence of perfect Euler cuboids. It is associated with a certain polynomial Diophantine equation of the order 10. In this paper a structural theorem for the solutions of this Diophantine equation is proved and some examples of its application are considered.

math.NT↗
arXiv2011

A note on the first cuboid conjecture

Recently the problem of constructing a perfect Euler cuboid was related with three conjectures asserting the irreducibility of some certain three polynomials depending on integer parameters. In this paper a partial result toward proving the first cuboid conjecture is obtained. The polynomial which, according to this conjecture, should be irreducible over integers is proved to have no integer roots.

math.NT↗
arXiv2011

Perfect cuboids and irreducible polynomials

The problem of constructing a perfect cuboid is related to a certain class of univariate polynomials with three integer parameters $a$, $b$, and $u$. Their irreducibility over the ring of integers under certain restrictions for $a$, $b$, and $u$ would mean the non-existence of perfect cuboids. This irreducibility is conjectured and then verified numerically for approximately 10000 instances of $a$, $b$, and $u$.

math.NT↗
arXiv2011

A note on the $\Sopfr(n)$ function

The $\Sopfr(n)$ function is defined as the sum of prime factors of $n$ each of which is taken with its multiplicity. This function is studied numerically. The analogy between $\Sopfr(n)$ and the primes distribution function is drawn and some conjectures for prime numbers formulated in terms of the $\Sopfr(n)$ function are suggested.

math.NT↗
arXiv2010

A counterexample to Khabibullin's conjecture for integral inequalities

Khabibullin's conjecture for integral inequalities has two numeric parameters $n$ and $α$ in its statement, $n$ being a positive integer and $α$ being a positive real number. This conjecture is already proved in the case where $n>0$ and $0<α\leq 1/2$. However, for $α>1/2$ it is not always valid. In this paper a counterexample is constructed for $n=2$ and $α=2$. Then Khabibullin's conjecture is reformulated in a way suitable for all $α>0$.

math.CA↗
arXiv2010

Direct and inverse conversion formulas associated with Khabibullin's conjecture for integral inequalities

Khabibullin's conjecture deals with two linear integral inequalities for some non-negative continuous function $q(t)$. The integral in the first of these two inequalities converts $q(t)$ into another function of one variable $g(t)$. This integral yields the direct conversion formula. An inverse conversion formula means a formula expressing $q(t)$ back through $g(t)$. Such an inverse conversion formula is derived.

math.CA↗
arXiv2009

Algorithm for generating orthogonal matrices with rational elements

Special orthogonal matrices with rational elements form the group SO(n,Q), where Q is the field of rational numbers. A theorem describing the structure of an arbitrary matrix from this group is proved. This theorem yields an algorithm for generating such matrices by means of random number routines.

cs.MS↗
arXiv2007

On deformations of metrics and their associated spinor structures

Smooth deformations of a Minkowski type metric in a four-dimensional space-time manifold are considered. Deformations of the basic spin-tensorial fields associated with this metric are calculated and their application to calculating the energy-momentum tensor of a massive spin 1/2 particle is shown.

math.DG↗