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Related papers: Boundary behaviour of Hurwitz schemes

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In this survey article we give an overview of how noncongruence modular curves can be viewed as Hurwitz moduli spaces of covers of elliptic curves at most branched above the origin. We describe some natural questions that arise, and…

Number Theory · Mathematics 2025-10-15 William Y. Chen

This is a survey paper dealing with moduli aspects of curves over finite fields. It discusses counting points of moduli spaces, relations with modular forms and stratifications on moduli spaces.

Algebraic Geometry · Mathematics 2022-10-27 Gerard van der Geer

We give finite presentations for the fundamental group of moduli stacks of smooth Weierstrass curves over complex projective space P^n which extend the classical result for elliptic curves to positive dimensional base. We thus get natural…

Algebraic Geometry · Mathematics 2007-12-21 Michael Lönne

We prove that if a finite group $G$ acts smoothly on a manifold $M$ so that all the isotropy subgroups are abelian groups with rank $\leq k$, then $G$ acts freely and smoothly on $M \times \bbS^{n_1} \times...\times \bbS^{n_k}$ for some…

Algebraic Topology · Mathematics 2012-04-30 Ozgun Unlu , Ergun Yalcin

We construct smooth $\mathbb{C}^*$-actions on the moduli spaces of super $J$-holomorphic curves as well as super stable curves and super stable maps of genus zero and fixed tree type such that their reduced spaces are torus invariant.…

Differential Geometry · Mathematics 2023-06-19 Enno Keßler , Artan Sheshmani , Shing-Tung Yau

We prove that, given any smooth action of a compact quantum group (in the sense of \cite{rigidity}) on a compact smooth manifold satisfying some more natural conditions, one can get a Riemannian structure on the manifold for which the…

Operator Algebras · Mathematics 2015-03-19 Debashish Goswami , Soumalya Joardar

Analogue of classical Hurwitz numbers is defined in the work for regular coverings of surfaces with marked points by seamed surfaces. Class of surfaces includes surfaces of any genus and orientability, with or without boundaries; coverings…

Geometric Topology · Mathematics 2007-09-25 A. V. Alexeevski , S. M. Natanzon

Active liquid crystals or active gels are soft materials which can be physically realised e.g. by preparing a solution of cytoskeletal filaments interacting with molecular motors. We study the hydrodynamics of an active liquid crystal in a…

Soft Condensed Matter · Physics 2007-06-29 D. Marenduzzo , E. Orlandini , M. E. Cates , J. M. Yeomans

By the work of Brodzki-Niblo-Nowak-Wright and Monod, topological amenability of a continuous group action can be characterized using uniformly finite homology groups or bounded cohomology groups associated to this action. We show that…

Dynamical Systems · Mathematics 2021-08-11 Yongle Jiang

We study profinite actions of residually finite groups in terms of weak containment. We show that two strongly ergodic profinite actions of a group are weakly equivalent if and only if they are isomorphic. This allows us to construct…

Group Theory · Mathematics 2011-09-20 Miklós Abért , Gábor Elek

We prove a number of results linking properties of actions by compact groups (both quantum and classical) on Banach spaces, such as uniform continuity, spectrum finiteness and extensibility of the actions across several constructions.…

Operator Algebras · Mathematics 2025-01-22 Alexandru Chirvasitu

The equivariant cohomology for actions of compact connected abelian groups and elementary abelian p-groups have been widely studied in the last decades. We study some of these results on actions of finite cyclic groups over a field of…

Algebraic Topology · Mathematics 2022-06-24 Sergio Chaves

In this article we collect a series of observations that constrain actions of many groups on compact manifolds. In particular, we show that "generic" finitely generated groups have no smooth volume preserving actions on compact manifolds…

Dynamical Systems · Mathematics 2008-05-15 David Fisher , Lior Silberman

We study new effective curve classes on the moduli space of stable pointed rational curves given by the fixed loci of subgroups of the permutation group action. We compute their numerical classes and provide a strategy for writing them as…

Algebraic Geometry · Mathematics 2014-06-10 Han-Bom Moon , David Swinarski

In this paper, we study stable ergodicity of the action of groups of diffeomorphisms on smooth manifolds. Such actions are known to exist only on one-dimensional manifolds. The aim of this paper is to introduce a geometric method to…

Dynamical Systems · Mathematics 2025-01-30 Abbas Fakhari , Meysam Nassiri , Hesam Rajabzadeh

In this paper we study actions of finite groups on closed connected aspherical manifolds. Under some assumptions on the outer automorphism group of the fundamental group of a closed connected aspherical manifold $M$, we prove that the…

Geometric Topology · Mathematics 2025-06-13 Jordi Daura Serrano

Given a smooth, projective curve $Y$, a point $y_0 \in Y$, a positive integer $n$, and a transitive subgroup $G$ of the symmetric group $S_{d}$ we study smooth, proper families, parameterized by algebraic varieties, of pointed degree $d$…

Algebraic Geometry · Mathematics 2025-10-21 Vassil Kanev

We study the behaviors of quantum groups under an edge contraction. We show that there exists an explicit embedding induced by an edge contraction operation. We further conjecture that this explicit embedding is a section of an explicit…

Quantum Algebra · Mathematics 2023-09-01 Yiqiang Li

Mathematical core of quantum mechanics is the theory of unitary representations of symmetries of physical systems. We argue that quantum behavior is a natural result of extraction of "observable" information about systems containing…

Quantum Physics · Physics 2011-10-03 Vladimir V. Kornyak

We study the locus of smooth hypersurfaces inside the Hilbert scheme of a smooth projective complex variety. In the spirit of scanning, we construct a map to a continuous section space of a projective bundle, and show that it induces an…

Algebraic Geometry · Mathematics 2026-03-11 Alexis Aumonier
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