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We define a new perverse t-exact pullback operation on derived categories of constructible sheaves which generalizes most perverse t-exact functors in sheaf theory, such as microlocalization, the Fourier-Sato transform and vanishing cycles.…

Algebraic Geometry · Mathematics 2025-10-21 Adeel A. Khan , Tasuki Kinjo , Hyeonjun Park , Pavel Safronov

One fundamental consequence of a scheme $X$ being proper is that the functor classifying maps from $X$ to any other suitably nice scheme or algebraic stack is representable by an algebraic stack. This result has been generalized by…

Algebraic Geometry · Mathematics 2019-07-30 Daniel Halpern-Leistner , Anatoly Preygel

Effective descent morphisms, originally defined in Grothendieck descent theory, form a class of special morphisms within a category. Essentially, an effective descent morphism enables bundles over its codomain to be fully described as…

Category Theory · Mathematics 2024-11-05 Fernando Lucatelli Nunes , Rui Prezado

In this paper we study flatness of the restriction on some special subgerms (e.g. the reduction and the unmixed part) of the total space of a flat morphism over a smooth base space. We give a relationship between reducedness of the total…

Algebraic Geometry · Mathematics 2019-02-19 Công-Trình Lê

In this short note, we simply collect some known results about representing algebraic cycles by various kind of "nice" (e.g. smooth, local complete intersection, products of local complete intersection) algebraic cycles, up to rational…

Algebraic Geometry · Mathematics 2016-12-15 Marco Maggesi , Gabriele Vezzosi

We give a direct, purely arithmetical and elementary proof of the strong normalization of the cut-elimination procedure for full (i.e. in presence of all the usual connectives) classical natural deduction.

Logic · Mathematics 2009-05-07 René David , Karim Nour

The paper gives the sufficient condition formulated in the syntactical form for all codescent morphisms of a variety of universal algebras satisfying the amalgamation property to be effective. This result is further used in proving that all…

Category Theory · Mathematics 2009-08-14 Dali Zangurashvili

Let $A$ be a regular category with pushouts of regular epimorphisms by regular epimorphism and $Reg(A)$ the category of regular epimorphisms in $A$. We prove that every regular epimorphism in $Reg(A)$ is an effective descent morphism if,…

Category Theory · Mathematics 2015-04-20 Tomas Everaert

An abstract mathematical framework is presented in this paper as a unification of several deformed or generalized algebra proposed recently in the context of generalized statistical theories intended to treat certain complex thermodynamic…

Statistical Mechanics · Physics 2020-10-20 Aziz El Kaabouchi , Laurent Nivanen , Qiuping A. Wang , Jean-Pierre Badiali , Alain Le Méhauté

A universal cycle is a cyclic sequence in which each object of a combinatorial family appears exactly once as a contiguous window. While such cycles are well understood for many discrete structures and linear subspaces, the case of affine…

Combinatorics · Mathematics 2026-05-20 Ming-Hsuan Kang , Shin-Hsun Chou

We prove that the vanishing of the functoriality morphism for the \'etale fundamental group between smooth projective varieties over an algebraically closed field of characteristic $p>0$ forces the same property for the fundamental groups…

Algebraic Geometry · Mathematics 2017-05-26 Hélène Esnault , Vasudevan Srinivas

We strengthen the standard bifurcation theorems for saddle-node, transcritical, pitchfork, and period-doubling bifurcations of maps. Our new formulation involves adding one or two extra terms to the standard truncated normal forms with…

Dynamical Systems · Mathematics 2022-06-13 Paul A. Glendinning , David J. W. Simpson

In this paper, we investigate the structure of the most general kind of substitution shifts, including non-minimal ones, and allowing erasing morphisms. We prove the decidability of many properties of these morphisms with respect to the…

Dynamical Systems · Mathematics 2024-04-03 Marie-Pierre Béal , Dominique Perrin , Antonio Restivo

We characterise the slices of the category of graphs that are algebraically universal in terms of the structure of the slicing graph. In particular, we show that algebraic universality is obtained if, and only if, the slicing graph contains…

Combinatorics · Mathematics 2023-10-06 Ioannis Eleftheriadis

We provide results on the smoothness of normalisers in connected reductive algebraic groups $G$ over fields $k$ of positive characteristic $p$. Specifically we we give bounds on $p$ which guarantee that normalisers of subalgebras of…

Group Theory · Mathematics 2016-01-06 Sebastian Herpel , David I. Stewart

We prove constructively the existence of surjective morphisms from affine space onto certain open subvarieties of affine space of the same dimension. For any algebraic set $Z\subset \mathbb{A}^{n-2}\subset \mathbb{A}^{n}$, we construct an…

Algebraic Geometry · Mathematics 2023-08-22 Viktor Balch Barth

Given a recollement of three proper dg algebras over a noetherian commutative ring, e.g. three algebras which are finitely generated over the base ring, which extends one step downwards, it is shown that there is a short exact sequence of…

Representation Theory · Mathematics 2023-07-06 Haibo Jin , Dong Yang , Guodong Zhou

We introduce a class of normal complex spaces having only mild sin-gularities (close to quotient singularities) for which we generalize the notion of a (analytic) fundamental class for an analytic cycle and also the notion of a relative…

Complex Variables · Mathematics 2017-10-24 Daniel Barlet , Jón Magnússon

The categories with noninvertible morphisms are studied analogously to the semisupermanifolds with noninvertible transition functions. The concepts of regular n-cycles, obstruction and the regularization procedure are introduced and…

Mathematical Physics · Physics 2007-05-23 Steven Duplij , Wladyslaw Marcinek

We give a conceptual explanation of universal deformation formulas for unital associative algebras and prove some results on the structure of their moduli spaces. We then generalize universal deformation formulas to other types of algebras…

Algebraic Topology · Mathematics 2013-08-19 Elisabeth Remm , Martin Markl