Universidad de Costa Rica

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19942026

most citedAncient human genomes suggest three ancestral populations for present-day Europeans

1.5k citations

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11 papers · 1 filter

math.AG2022

Singularities of determinantal pure pairs

Javier Carvajal-Rojas, Arnaud Vilpert

Let $X$ be a generic determinantal affine variety over a perfect field of characteristic $p \geq 0$ and $P \subset X$ be a standard prime divisor generator of $\mathrm{Cl}(X) \cong…

math.AG2020

Stratifications on the Nilpotent Cone of the moduli space of Hitchin pairs

Peter B. Gothen, Ronald A. Zúñiga-Rojas

We consider the problem of finding the limit at infinity (corresponding to the downward Morse flow) of a Higgs bundle in the nilpotent cone under the natural $C^{*}$ -action…

math.AG2020

Extension of torsors and prime to $p$ fundamental group scheme

Marco Antei, Jimmy Calvo-Monge

Let $R$ be a discrete valuation ring with fraction field $K$ . Let $X$ be a proper and faithfully flat $R$ -scheme, endowed with a section $x \in X (R)$ , with connected and reduced ge…

math.AG2018

Models of torsors over affine spaces

Marco Antei, Jorge A. Esquivel A

Let $X := A_{R}^{n}$ be the $n$ -dimensional affine space over a discrete valuation ring $R$ with fraction field $K$ . We prove that any pointed torsor $Y$ over $\mathbb{A}^{n…

math.AG2017★ 5 cited

Bertini Theorems for $F$ -signature and Hilbert-Kunz multiplicity

Javier Carvajal-Rojas, Karl Schwede, Kevin Tucker

We show that Bertini theorems hold for $F$ -signature and Hilbert--Kunz multiplicity. In particular, if $X \subseteq P^{n}$ is normal and quasi-projective with $F$ -signature…

math.AG2017★ 2 cited

Nori fundamental gerbe of essentially finite covers and Galois closure of towers of torsors

M. Antei, I. Biswas, M. Emsalem +2

We prove the existence of a Galois closure for towers of torsors under finite group schemes over a proper, geometrically connected and geometrically reduced algebraic stack $X$ ove…