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In this article, we summarize the results on symmetric conformal geometries. We review the results following from the general theory of symmetric parabolic geometries and prove several new results for symmetric conformal geometries. In…

Differential Geometry · Mathematics 2016-02-08 Jan Gregorovič , Lenka Zalabová

Questions related to deformations of germs of finite morphisms of smooth surfaces are discussed. A classification of the four-sheeted germs of finite covers $F: (U,o')\to (V,o)$ is given up to smooth deformations, where $(U,o')$ and $(V,o)$…

Algebraic Geometry · Mathematics 2019-01-16 Vik. S. Kulikov

We introduce a lifting property for local cohomology, which leads to a unified treatment of the dualizing complex for flat morphisms with semi-log-canonical, Du Bois or F-pure fibers. As a consequence we obtain that, in all 3 cases, the…

Algebraic Geometry · Mathematics 2018-10-23 János Kollár , Sándor J Kovács

We answer a question of Koll\'ar and Kov\'acs by constructing a flat projective morphism to a smooth curve whose fibers are Cohen--Macaulay and reduced, whose generic fiber is smooth, and for which the first cohomology of the structure…

Algebraic Geometry · Mathematics 2026-05-21 Jihao Liu

The notion of flat minima has played a key role in the generalization studies of deep learning models. However, existing definitions of the flatness are known to be sensitive to the rescaling of parameters. The issue suggests that the…

Machine Learning · Statistics 2019-01-29 Yusuke Tsuzuku , Issei Sato , Masashi Sugiyama

Given an essentially finite type morphism of schemes f: X --> Y and a positive integer d, let f^{d}: X^{d} --> Y denote the natural map from the d-fold fiber product, X^{d}, of X over Y and \pi_i: X^{d} --> X the i'th canonical projection.…

Algebraic Geometry · Mathematics 2011-01-24 Luchezar L. Avramov , Srikanth B. Iyengar

The class of the hypercomplex pseudo-Hermitian manifolds is considered. The flatness of the considered manifolds with the 3 parallel complex structures is proved. Conformal transformations of the metrics are introduced. The conformal…

Differential Geometry · Mathematics 2012-03-27 Kostadin Gribachev , Mancho Manev , Stancho Dimiev

We study the pullback of the stable and augmented base locus under a finite surjective morphism between normal varieties over a perfect field.

Algebraic Geometry · Mathematics 2022-09-19 Tanuj Gomez

We characterize universally generalizing morphisms which satisfy descent of algebraic cycles integrally as those universally generalizing morphisms which are surjective with generically reduced fibres. In doing so, we introduce a naive…

Algebraic Geometry · Mathematics 2015-06-09 Johannes Anschütz

A condition on an affine central subalgebra $Z$ of a noetherian algebra $A$ of finite Gelfand-Kirillov dimension, which we call here \emph{unruffledness}, is shown to be equivalent in some circumstances to the flatness of $A$ as a…

Rings and Algebras · Mathematics 2007-05-23 Kenneth A. Brown

We consider modified scalar curvature functions for Riemannian manifolds equipped with smooth measures. Given a Riemannian submersion whose fiber transport is measure-preserving up to constants, we show that the modified scalar curvature of…

Differential Geometry · Mathematics 2007-05-23 John Lott

In this work, the dual flatness, which is connected with Statistics and Information geometry, of general $(\alpha,\beta)$-metrics (a new class of Finsler metrics) is studied. A nice characterization for such metrics to be dually flat under…

Differential Geometry · Mathematics 2015-02-05 Changtao Yu

We study algebraicity and smoothness of fixed point stacks for flat group schemes which have a finite composition series whose factors are either reductive or proper, flat, finitely presented, acting on algebraic stacks with affine,…

Algebraic Geometry · Mathematics 2022-09-19 Matthieu Romagny

We prove some estimates on the spectrum of the Laplacian of the total space of a Riemannian submersion in terms of the spectrum of the Laplacian of the base and the geometry of the fibers. When the fibers of the submersions are compact and…

Differential Geometry · Mathematics 2010-01-07 G. Pacelli Bessa , J. Fabio Montenegro , Paolo Piccione

In our previous paper math.QA/0409261, we defined a deformation of the group algebra of the group of even elements of a Coxeter group W, and showed that it is flat for all values of parameters if and only if all the rank 3 parabolic…

Quantum Algebra · Mathematics 2007-05-23 Pavel Etingof , Eric Rains

The focus of this article is the study of a certain type of singularities and their transfer properties in a universally equidimensional morphism (i.e. an open morphism with constant pure-dimensional fibers). The singularities of interest…

Algebraic Geometry · Mathematics 2025-07-08 Mohamed Kaddar

We characterize general pseudo-harmonic morphisms from a Riemannian manifold to a Hermitian manifold as pseudo horizontally weakly conformal maps with an additional property. We study to what extent we can (locally) describe these…

Differential Geometry · Mathematics 2007-12-18 Radu Slobodeanu

This paper studies a general notion of flatness in the enriched context: P-flatness where the parameter P stands for a class of presheaves. One obtains a completion of a category A by considering the category Flat_P(A) of P-flat presheaves…

Category Theory · Mathematics 2007-05-23 Vincent Schmitt

The theory of moduli of morphisms on P^n generalizes the study of rational maps on P^1. This paper proves three results about the space of morphisms on P^n of degree d > 1, and its quotient by the conjugation action of PGL(n+1). First, we…

Dynamical Systems · Mathematics 2009-08-24 Alon Levy

The proof of Theorem 7.12 of "Uniqueness of smooth cohomology theories" by the authors of this note is not correct. The said theorem identifies the flat part of a differential extension of a generalized cohomology theory E with ER/Z (there…

K-Theory and Homology · Mathematics 2010-07-19 Ulrich Bunke , Thomas Schick