activity
20102026
most citedA general extension theorem for cohomology classes on non reduced analytic spaces

39 citations · 187 across the 37 of their papers we have counts for

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21 papers · 1 filter

math.AG2026

Positivity of compact Kähler varieties admitting an int-amplified endomorphism

Shin-ichi Matsumura, Guolei Zhong

We study compact Kähler varieties admitting int-amplified endomorphisms from the viewpoint of positivity of tangent sheaves. Our main result shows that the tangent sheaf of such a…

math.AG2026

A note on compact Kähler varieties with pseudo-effective tangent sheaf

Shin-ichi Matsumura, Guolei Zhong

In this paper, we discuss recent developments and open problems concerning the geometry of compact Kähler varieties whose tangent sheaves are pseudo-effective in a strong sense. As…

math.AG2026

A flatness criterion for pseudo-effective sheaves on compact Kähler spaces

Junyan Cao, Ya Deng, Shin-ichi Matsumura

In this paper, we prove that if is a pseudo-effective sheaf with vanishing first Chern class on a klt compact Kähler space , then, after passing to a finite quasi-étale cove…

math.AG2025

Beauville--Bogomolov--Yau decomposition for Kähler generalized pairs

Shin-ichi Matsumura, Juanyong Wang, Xiaojun Wu +1

In this paper, we establish the Beauville--Bogomolov--Yau decomposition for generalized pairs in the Kähler setting, thereby extending this structure theorem to the natural framewo…

math.AG2025

On compact Kähler manifolds with pseudo-effective tangent bundle

Shin-ichi Matsumura, Chenghao Qing

In this paper, we prove that a compact Kähler manifold with pseudo-effective (resp. singular positively curved) tangent bundle admits a smooth (resp. locally constant) rational…

math.AG2024

Singular Nakano positivity of direct image sheaves of adjoint bundles

Takahiro Inayama, Shin-ichi Matsumura, Yuta Watanabe

In this paper, we consider a proper Kähler fibration and a singular Hermitian line bundle on with semi-positive curvature. We prove that the direct…

math.AG2024

Minimal projective varieties satisfying Miyaoka's equality

Masataka Iwai, Shin-ichi Matsumura, Niklas Müller

In this paper, we establish a structure theorem for minimal projective klt varieties that satisfiy Miyaoka's equality . Specifically, we prove that the cano…

math.AG2023

Positivity of tangent sheaves of projective varieties -- the structure of MRC fibrations

Masataka Iwai, Shin-ichi Matsumura, Guolei Zhong

In this paper, we extend the structure theorem for smooth projective varieties with nef tangent bundle to projective klt varieties whose tangent sheaf is either positively curved o…

math.AG2023★ 3 cited

Compact Kähler three-folds with nef anti-canonical bundle

Shin-ichi Matsumura, Xiaojun Wu

In this paper, we prove that a non-projective compact Kähler three-fold with nef anti-canonical bundle is, up to a finite étale cover, one of the following: a manifold with vanishi…

math.AG2022

Open problems on structure of positively curved projective varieties

Shin-ichi Matsumura

We provide supplements and open problems related to structure theorems for maximal rationally connected fibrations of certain positively curved projective varieties, including smoo…

math.AG2022★ 4 cited

On the minimal model program for projective varieties with pseudo-effective tangent sheaf

Shin-ichi Matsumura

In this paper, we develop a theory of pseudo-effective sheaves on normal projective varieties. As an application, by running the minimal model program, we show that projective klt…

math.AG2022★ 11 cited

The Nonvanishing problem for varieties with nef anticanonical bundle

Vladimir Lazić, Shin-ichi Matsumura, Thomas Peternell +2

We prove that if is a threefold pair with mild singularities such that is nef, then the numerical class of is effective.

math.AG2021★ 6 cited

Structure theorem for projective klt pairs with nef anti-canonical divisor

Shin-ichi Matsumura, Juanyong Wang

In this paper, we establish a structure theorem for projective klt pairs with nef anti-log canonical divisor; specifically, we prove that, up to replacing with a finite…

math.AG2021★ 5 cited

Strictly nef divisors on K-trivial fourfolds

Haidong Liu, Shin-ichi Matsumura

In this paper, we prove the ampleness conjecture and Serrano's conjecture for strictly nef divisors on K-trivial fourfolds. Specifically, we show that any strictly nef divisors on…

math.AG2020★ 5 cited

On asymptotic base loci of relative anti-canonical divisors of algebraic fiber spaces

Sho Ejiri, Masataka Iwai, Shin-ichi Matsumura

In this paper, we study the relative anti-canonical divisor of an algebraic fiber space , and we reveal relations among positivity conditions of ,…

math.AG2019★ 12 cited

Projective klt pairs with nef anti-canonical divisor

Frédéric Campana, Junyan Cao, Shin-ichi Matsumura

In this paper, we study a projective klt pair with the nef anti-log canonical divisor and its maximally rationally connected fibration .…

math.AG2019★ 21 cited

On projective manifolds with pseudo-effective tangent bundle

Genki Hosono, Masataka Iwai, Shin-ichi Matsumura

In this paper, we develop the theory of singular hermitian metrics on vector bundles. As an application, we give a structure theorem of a projective manifold with pseudo-effect…

math.AG2018★ 1 cited

Variation of numerical dimension of singular hermitian line bundles

Shin-ichi Matsumura

The purpose of this paper is to give two supplements for vanishing theorems: One is a relative version of the Kawamata-Viehweg-Nadel type vanishing theorem, which is obtained from…

math.AG2017★ 39 cited

A general extension theorem for cohomology classes on non reduced analytic spaces

Junyan Cao, Jean-Pierre Demailly, Shin-Ichi Matsumura

The main purpose of this paper is to generalize the celebrated L extension theorem of Ohsawa-Takegoshi in several directions : the holomorphic sections to extend are taken in…

math.AG2014★ 8 cited

Versions of injectivity and extension theorems

Yoshinori Gongyo, Shin-ichi Matsumura

We give an analytic version of the injectivity theorem by using multiplier ideal sheaves, and prove some extension theorems for the adjoint bundle of dlt pairs. Moreover, by combin…

math.AG2010★ 2 cited

Restricted volumes and divisorial Zariski decompositions

Shin-ichi Matsumura

We give a relation between the existence of a Zariski decomposition and the behavior of the restricted volume of a big divisor on a smooth (complex) projective variety. Moreover, w…