English
Related papers

Related papers: Algebraic monodromy and obstructions to formality

200 papers

I extend the definitions of schemes relative to monoids with zero - and therefore, toric geometry - to the world of formal schemes. This expands the usual framework to include, for instance, models for Mumford's degenerating Abelian…

Algebraic Geometry · Mathematics 2015-05-29 Andrew W. Macpherson

We prove new structural results for the rational homotopy type of the classifying space $B\operatorname{aut}(X)$ of fibrations with fiber a simply connected finite CW-complex $X$. We first study nilpotent covers of $B\operatorname{aut}(X)$…

Algebraic Topology · Mathematics 2025-10-15 Alexander Berglund , Tomáš Zeman

We prove metric rigidity for complete manifolds supporting solutions of certain second order differential systems, thus extending classical works on a characterization of space-forms. In the route, we also discover new characterizations of…

Differential Geometry · Mathematics 2009-03-06 Stefano Pigola , Michele Rimoldi

We attack the question of E_2-formality of differential graded algebras over prime fields via obstruction theory. We are able to prove that E_2-algebras whose cohomology ring is a polynomial algebra on even degree classes are intrinsically…

Algebraic Topology · Mathematics 2026-05-26 Geoffroy Horel

We study the special fibers of a certain class of absolutely simple abelian varieties over number fields with endomorphism rings $\bz$ and possessing $l$-adic monodromy groups of the least possible rank. We also study the Dirichlet density…

Number Theory · Mathematics 2017-11-01 Steve Thakur

We study a natural generalization of inverse systems of finite regular covering spaces. A limit of such a system is a fibration whose fibres are profinite topological groups. However, as shown in a previous paper (Conner-Herfort-Pavesic:…

Algebraic Topology · Mathematics 2019-01-09 Gregory R. Conner , Wolfgang Herfort , Petar Pavešić

Let $X$ be a variety over a complete nontrivially valued field $K$. We construct an algebraizable formal model for the analytification of $X$ in the case $X$ admits a closed embedding into a toric variety. By algebraizable we mean that the…

Algebraic Geometry · Mathematics 2023-03-27 Desmond Coles , Netanel Friedenberg

If $X$ is a variety with an additional structure $\xi$, such as a marked point, a divisor, a polarization, a group structure and so forth, then it is possible to study whether the pair $(X,\xi)$ is defined over the field of moduli. There…

Algebraic Geometry · Mathematics 2023-11-29 Giulio Bresciani

It is, by now, classical that lattices in higher rank semisimple groups have various rigidity properties. In this work, we add another such rigidity property to the list: uniform stability with respect to the family of unitary operators on…

Group Theory · Mathematics 2023-07-11 Lev Glebsky , Alexander Lubotzky , Nicolas Monod , Bharatram Rangarajan

Let $X$ be a simply connected path connected topological space which is formal in the sense of rational homotopy theory. Let $Y=X\cup_\alpha\mathbb{D}^{n}$ where $\alpha:\mathbb{S}^{n-1}\to X$ is a non-torsion element. Then we obtain a…

Algebraic Topology · Mathematics 2018-08-21 Prateep Chakraborty , Parameswaran Sankaran

We prove structure theorems for the moduli stack of elliptic curves equipped with $G$-structures, where $G$ is a finite 2-generated metabelian group. In particular, we show that if $G$ has exponent $e$, then there is a subgroup $H\le…

Algebraic Geometry · Mathematics 2017-10-17 William Yun Chen , Pierre Deligne

We identify the obstructions for the functoriality and the uniqueness of the totalization functor, (partially) defined on the category of simplicial objects in the homotopy category of a stable model category, and we use a result from the…

Algebraic Topology · Mathematics 2014-10-01 Crichton Ogle , Andrew Salch

We review the basic elements of the geometrical formalism for description of gauge fields and the theory of invariant connections, and their applications to the coset space dimensional reduction of Yang-Mills theories. We also discuss the…

Mathematical Physics · Physics 2007-05-23 Yuri A. Kubyshin

The notion of a (stably) decomposable fiber bundle is introduced. In low dimensions, for torus fiber bundles over a circle the notion translates into a property of elements of the special linear group of integral matrices. We give a…

Algebraic Topology · Mathematics 2017-03-21 Mahir Bilen Can , Mustafa Topkara

We will introduce formal frames of manifolds, which are a generalization of ordinary frames. Their fundamental properties are discussed. In particular, canonical forms are introduced, and torsions are defined in terms of them as a…

Differential Geometry · Mathematics 2023-03-15 Taro Asuke

In this paper, we consider an obstruction-theoretical construction of characteristic classes of fiber bundles by simplicial method. We can get a certain obstruction class for a deformation of $C_\infty$-algebra models of fibers and a…

Algebraic Topology · Mathematics 2019-05-30 Takahiro Matsuyuki

We develop technics of birational geometry to study automorphisms of affine surfaces admitting many distinct rational fibrations, with a particular focus on the interactions between automorphisms and these fibrations. In particular, we…

Algebraic Geometry · Mathematics 2009-06-22 Jérémy Blanc , Adrien Dubouloz

By using Thurston's bending construction we obtain a sequence of faithful discrete representations \rho _n of the fundamental group of a closed hyperbolic 3-manifold fibering over the circle into the isometry group Iso H^4 of the hyperbolic…

Geometric Topology · Mathematics 2016-09-07 Leonid Potyagailo

We construct three new families of fibrations $\pi : S \to B$ where $S$ is an algebraic complex surface and $B$ a curve that violate Xiao's conjecture relating the relative irregularity and the genus of the general fiber. The fibers of…

Algebraic Geometry · Mathematics 2015-06-30 Alberto Albano , Gian Pietro Pirola

This work deals with the topological classification of germs of singular foliations on $(\mathbb C^{2},0)$. Working in a suitable class of foliations we fix the topological invariants given by the separatrix set, the Camacho-Sad indices and…

Dynamical Systems · Mathematics 2017-09-19 David Marín , Jean-François Mattei , Éliane Salem