arXiv subjects

Michael Tsfasman

Publications and source records attributed to Michael Tsfasman.

4 recordsLinked to original sources

arXiv2026

Quadratic residue patterns of length 4 and 5

We generalize the results of the first part of the paper by Kiritchenko, Tsfasman, Vl\u{a}du\c{t} and Zakharevich on quadratic residue patterns to the case of arbitrary words over the alphabet $\{R, N\}$ of length $l = 4$ and $l = 5$. First, we obtain explicit formulas for the number of occurrences of a given pattern $S$ in the sequence of quadratic residues and nonresidues modulo a prime $p$. These formulas are expressed in terms of Frobenius traces on a finite collection of low-genus hyperelliptic curves. Second, using a generalized Sato-Tate approach, we describe the limiting distributions of the normalized error term for $l = 4$.

math.NT↗

arXiv2024

Quadratic residue patterns, algebraic curves and a K3 surface

Quadratic residue patterns modulo a prime are studied since 19th century. In the first part we extend existing results on the number of consecutive $\ell$-tuples of quadratic residues, studying corresponding algebraic curves and their jacobians, which happen to be products of jacobians of hyperelliptic curves. In the second part we state the last unpublished result of Lydia Goncharova on squares such that their differences are also squares, reformulate it in terms of algebraic geometry of a K3 surface, and prove it. The core of this theorem is an unexpected relation between the number of points on the K3 surface and that on a CM elliptic curve.

math.AG↗

arXiv2005

Asymptotic behaviour of the Euler-Kronecker constant

This appendix to the beautiful paper of Ihara puts it in the context of infinite global fields of our papers. We study the behaviour of Euler--Kronecker constant $γ\_{K}$ when the discriminant (respectively, the genus) tends to infinity. Results of our paper easily give us good lower bounds on the ratio ${γ\_{K}/\log\sqrt{| d\_{K}|}}$. In particular, for number fields, under the generalized Riemann hypothesis we prove $$\liminf{γ\_{K}\over\log\sqrt{| d\_{K}|}}\ge -0.26049...$$ Then we produce examples of class field towers, showing that $$\liminf{γ\_{K}\over\log\sqrt{| d\_{K}|}}\le -0.17849...$$}

math.NT↗

arXiv2002

Infinite global fields and the generalized Brauer--Siegel theorem

The paper has two purposes. First, we start to develop a theory of infinite global fields, i.e., of infinite algebraic extensions either of ${\mathbb{Q}}$ or of ${\mathbb{F}}_r(t)$. We produce a series of invariants of such fields, and we introduce and study a kind of zeta-function for them. Second, for sequences of number fields with growing discriminant we prove generalizations of the Odlyzko--Serre bounds and of the Brauer--Siegel theorem, taking into account non-archimedean places. This leads to asymptotic bounds on the ratio ${{\log hR}/\log\sqrt{| D|}}$ valid without the standard assumption ${n/\log\sqrt{| D|}}\to 0,$ thus including, in particular, the case of unramified towers. Then we produce examples of class field towers, showing that this assumption is indeed necessary for the Brauer--Siegel theorem to hold. As an easy consequence we ameliorate on existing bounds for regulators.

math.NT↗