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In this article, we prove the existence of common fixed points for a pair of maps on a $q$-spherically complete $T_0$-ultra-quasi-metric space. The present article is a generalization, in the assymmetric setting of the paper of Rao et…

General Topology · Mathematics 2014-12-04 Collins Amburo Agyingi , Yaé Ulrich Gaba

We extend fundamental inequalities related to the canonical map of surfaces of general type to positive characteristic. Next, we classify surfaces on the Noether lines, i.e., even and odd Horikawa surfaces, in positive characteristic. We…

Algebraic Geometry · Mathematics 2013-01-11 Christian Liedtke

We show that a weak version of the canonical bundle formula holds for fibrations of relative dimension one. We provide various applications thereof, for instance, using the recent result of Xu and Zhang, we prove the log non-vanishing…

Algebraic Geometry · Mathematics 2018-04-11 Jakub Witaszek

Let X be a smooth quasiprojective subscheme of P^n of dimension m >= 0 over F_q. Then there exist homogeneous polynomials f over F_q for which the intersection of X and the hypersurface f=0 is smooth. In fact, the set of such f has a…

Algebraic Geometry · Mathematics 2017-04-03 Bjorn Poonen

The purpose of this note is to give an (esentially optimal) effective version of Matsusaka's Big theorem for smooth projective surfaces.

alg-geom · Mathematics 2008-02-03 Guillermo Fernández del Busto

In this paper, we use canonical bundle formulas to prove some generalizations of an old theorem of Kawamata on the semiampleness of nef and abundant log canonical divisors. In particular, we show that for klt pairs $(X,B)$ with $K_X+B$…

Algebraic Geometry · Mathematics 2022-09-07 Priyankur Chaudhuri

In this paper we prove a result on the effective generation of pluri-canonical linear systems on foliated surfaces of general type. Fix a function $P: \mathbb Z_{\geq 0}\to \mathbb Z $, then there exists an integer $N_1>0$ such that if…

Algebraic Geometry · Mathematics 2025-01-13 Christopher D. Hacon , Adrian Langer

This paper initiates the systematic study of the number of points of bounded height on symmetric squares of weak Fano varieties. We provide a general framework for establishing the point count on $\text{Sym}^2 X$. In the specific case of…

Number Theory · Mathematics 2025-06-10 Francesca Balestrieri , Kevin Destagnol , Julian Lyczak , Jennifer Park , Nick Rome

Let $k$ be an $F$-finite field containing an infinite perfect field of positive characteristic. Let $(X, \Delta)$ be a projective log canonical pair over $k$. In this note we show that, for a semi-ample divisor $D$ on $X$, there exists an…

Algebraic Geometry · Mathematics 2017-03-21 Hiromu Tanaka

We introduce the notion of mixed-$\omega$-sheaves and use it for the study of a relative version of Fujita's freeness conjecture. It is related to the Iitaka conjecture. We note that the notion of mixed-$\omega$-sheaves is a generalization…

Algebraic Geometry · Mathematics 2023-09-11 Osamu Fujino

In this paper we give an elementary proof of the Zariski-Lipman conjecture for log canonical spaces.

Algebraic Geometry · Mathematics 2015-01-12 Stefan Heuver

We give a proof the monodromy conjecture relating the poles of motivic zeta functions with roots of b-functions for isolated quasihomogeneous hypersurfaces, and more generally for semi-quasihomogeneous hypersurfaces. We also give a strange…

Algebraic Geometry · Mathematics 2023-09-26 Guillem Blanco , Nero Budur , Robin van der Veer

We prove that the non-vanishing conjecture and the log minimal model conjecture for projective log canonical pairs can be reduced to the non-vanishing conjecture for smooth projective varieties such that the boundary divisor is zero.

Algebraic Geometry · Mathematics 2017-11-22 Kenta Hashizume

We prove that any link admitting a diagram with a single negative crossing is strongly quasipositive. This answers a question of Stoimenow's in the (strong) positive. As a second main result, we give simple and complete characterizations of…

Geometric Topology · Mathematics 2022-09-05 Peter Feller , Lukas Lewark , Andrew Lobb

We formulate a conjecture on the behavior of the minimal free resolutions of sets of general points on arbitrary varieties embedded by complete linear series, in analogy with the well-known Minimal Resolution Conjecture for points in…

Algebraic Geometry · Mathematics 2007-05-23 Gavril Farkas , Mircea Mustata , Mihnea Popa

We give another alternative proof to the Kawamata semiampleness theorem for the log canonical divisors on klt varieties which are nef and abundant. After the first version of this article was posted to the e-print Arxiv, Prof. Fujino…

Algebraic Geometry · Mathematics 2019-03-22 Shigetaka Fukuda

We prove the Lipman-Zariski conjecture for complex surface singularities of genus one, and also for those of genus two whose link is not a rational homology sphere. As an application, we characterize complex $2$-tori as the only normal…

Algebraic Geometry · Mathematics 2021-05-07 Patrick Graf

Let $X$ be a smooth algebraic curve. Suppose that there exists a triple covering $f : X \to Y$ where $Y$ is a smooth algebraic curve. In this paper, we investigate the existence of morphisms from $X$ to the projective line $\mathbf{P}^1$…

Algebraic Geometry · Mathematics 2008-06-12 Dongsoo Shin

We prove that a log surface has only finitely many weakly log canonical projective models with klt singularities up to log isomorphism, by reducing the problem to the boundedness of their polarization.

Algebraic Geometry · Mathematics 2025-10-17 Daniil Serebrennikov

Using recent developments in the theory of mixed motives, we prove that the log Bloch conjecture holds for an open smooth complex surface if the Bloch conjecture holds for its compactification. This verifies the log Bloch conjecture for all…

Algebraic Geometry · Mathematics 2018-07-25 Qizheng Yin , Yi Zhu