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Related papers: Log abelian varieties over a log point

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In this paper we investigate fixed-point numbers and entropies of endomorphisms on abelian varieties. It was shown quite recently that the number of fixed-points of an iterated endomorphism on a simple complex torus is either periodic or…

Algebraic Geometry · Mathematics 2017-06-20 Thorsten Herrig

In this paper, we establish an innovative framework in logarithmic Hodge theory for toroidal varieties, introducing weighted toroidal structures and developing a systematic obstruction theory for Hodge classes. Building upon recent advances…

Algebraic Geometry · Mathematics 2025-09-30 Jiaming Luo

We give an efficient, deterministic algorithm to decide if two abelian varieties over a number field are isogenous. From this, we derive an algorithm to compute the endomorphism ring of an elliptic curve over a number field.

Number Theory · Mathematics 2020-02-28 Jeff Achter

We study the isogenies of certain abelian varieties over finite fields with non-commutative endomorphism algebras with a view to potential use in isogeny-based cryptography. In particular, we show that any two such abelian varieties with…

Number Theory · Mathematics 2020-01-03 Steve Thakur

This paper is a gentle introduction to the theory of quasi-log varieties by Ambro. We explain the fundamental theorems for the log minimal model program for log canonical pairs. More precisely, we give a proof of the base point free theorem…

Algebraic Geometry · Mathematics 2009-10-25 Osamu Fujino

The motivation of this work is to construct an analog of compactified moduli of abelian varieties and toric pairs in the case of non-commutative algebraic group G. We introduce a class of "stable reductive varieties" which contain connected…

Algebraic Geometry · Mathematics 2007-05-23 Valery Alexeev , Michel Brion

In this article we study the Honda-Tate theory for log abelian varieties over an fs log point $S=(\mathrm{Spec}(\mathbf{k}),M_S)$ for $\mathbf{k}=\mathbb{F}_q$ a finite field, generalizing the classical Honda-Tate theory for abelian…

Number Theory · Mathematics 2024-04-26 Xiaoyu Zhang , Heer Zhao

Fix an ordinary abelian variety defined over a finite field. The ideal class group of its endomorphism ring acts freely on the set of isogenous varieties with same endomorphism ring, by complex multiplication. Any subgroup of the class…

Number Theory · Mathematics 2017-01-26 Dimitar Jetchev , Benjamin Wesolowski

In this article we investigate the regularity properties of linear degenerations of flag varieties. We classify the linear degenerations of (partial) flag varieties that are smooth. Furthermore, we study the singular locus of irreducible…

Algebraic Geometry · Mathematics 2025-08-01 Sabino Di Trani

We estimate the fraction of isogeny classes of abelian varieties over a finite field which have a given characteristic polynomial P(T) modulo l. As an application we find the proportion of isogeny classes of abelian varieties with a…

Number Theory · Mathematics 2007-05-23 Joshua Holden

We show that isomorphisms of fundamental groups of elementary anabelian varieties -- varieties obtained as iterated fibrations of hyperbolic curves -- over sub-$p$-adic fields correspond bijectively to isomorphisms of varieties. Moreover,…

Number Theory · Mathematics 2026-04-29 Magnus Carlson

We survey the Mumford construction of degenerating abelian varieties, with a focus on the analytic version of the construction, and its relation to toric geometry. Moreover, we study the geometry and Hodge theory of multivariable…

Algebraic Geometry · Mathematics 2026-03-30 Philip Engel , Olivier de Gaay Fortman , Stefan Schreieder

Generalizing a method of Sutherland and the author for elliptic curves, we design a subexponential algorithm for computing the endomorphism rings of ordinary abelian varieties of dimension two over finite fields. Although its correctness…

Number Theory · Mathematics 2013-10-16 Gaetan Bisson

We study endomorphism rings of principally polarized abelian surfaces over finite fields from a computational viewpoint with a focus on exhaustiveness. In particular, we address the cases of non-ordinary and non-simple varieties. For each…

Number Theory · Mathematics 2025-03-13 Samuele Anni , Gaetan Bisson , Annamaria Iezzi , Elisa Lorenzo García , Benjamin Wesolowski

We describe all polarizations for all abelian varieties over a finite field in a fixed isogeny class corresponding to a squarefree Weil polynomial, when one variety in the isogeny class admits a canonical liftings to characteristic zero,…

Number Theory · Mathematics 2025-02-28 Jonas Bergström , Valentijn Karemaker , Stefano Marseglia

We define the geometric simpleness for toroidal groups. We give an example of quasi-abelian variety which is geometrically simple, but not simple. We show that any quasi-abelian variety is isogenous to a product of geometrically simple…

Complex Variables · Mathematics 2018-09-24 Yukitaka Abe

In this paper we study the \'etale cohomology groups associated to abelian varieties. We obtain necessary and sufficient conditions for an abelian variety to have semistable reduction (or purely additive reduction which becomes semistable…

Algebraic Geometry · Mathematics 2007-05-23 A. Silverberg , Yu. G. Zarhin

Given an integer $D$ and an ordinary isogeny class of abelian varieties defined over a finite field $\mathbb{F}_q$ with commutative $\mathbb{F}_q$-endomorphism algebra, we provide algorithms for computing all isogenies of degree dividing…

Number Theory · Mathematics 2026-01-30 Edgar Costa , Taylor Dupuy , Stefano Marseglia , David Roe , Christelle Vincent

In this paper, we provide a classification of certain points on Hilbert modular varieties over finite fields under a mild assumption on Newton polygon. Furthermore, we use this characterization to prove estimates for the size of isogeny…

Number Theory · Mathematics 2025-04-02 Tejasi Bhatnagar , Yu Fu

In a previous paper [FT1], for any logarithmic symplectic pair (X,D) of a symplectic manifold X and a simple normal crossings symplectic divisor D, we introduced the notion of log pseudo-holomorphic curve and proved a compactness theorem…

Symplectic Geometry · Mathematics 2019-10-14 Mohammad Farajzadeh-Tehrani