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Related papers: Flexibility of singularities and beyond

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We consider the conformal Einstein equations for massless collisionless gas cosmologies which admit an isotropic singularity. After developing the general theory, we restrict to spatially-homogeneous cosmologies. We show that the Cauchy…

General Relativity and Quantum Cosmology · Physics 2009-10-31 K. Anguige , K. P. Tod

The paper proposes a vector generalization of the basic concepts of the theory of complex variable: the concept of modulus and argument of complex number. The author introduces some generalizations of the notion of holomorphic functions and…

Complex Variables · Mathematics 2011-05-16 A. K. Bakhtin

This master's thesis contains an introduction to $A_\infty$-algebras and homological perturbation theory. We then discuss the formality of compact K\"ahler manifolds and present a direct proof of a homotopy transfer principle of…

Rings and Algebras · Mathematics 2021-07-08 Carl Felix Waller

In a first part we propose an introduction to multisymplectic formalisms, which are generalisations of Hamilton's formulation of Mechanics to the calculus of variations with several variables: we give some physical motivations, related to…

Mathematical Physics · Physics 2007-05-23 Frederic Helein

I review recent results obtained for extensions of general relativity formulated within the Palatini formalism, an approach in which metric and connection are treated as independent geometrical entities. The peculiar dynamics of these…

General Relativity and Quantum Cosmology · Physics 2011-12-08 Gonzalo J. Olmo

We use the recently derived form factor expansions of the diagonal two-point correlation function of the square Ising model to study the susceptibility for a magnetic field applied only to one diagonal of the lattice, for the isotropic…

Mathematical Physics · Physics 2009-11-13 S. Boukraa , S. Hassani , J. -M. Maillard , B. M. McCoy , N. Zenine

A theory of gravitation is constructed in which all homogeneous and isotropic solutions are nonsingular, and in which all curvature invariants are bounded. All solutions for which curvature invariants approach their limiting values approach…

General Relativity and Quantum Cosmology · Physics 2009-10-22 R. Brandenberger , V. Mukhanov , A. Sornborger

Using the theory of extensions of L-infinity algebras, we construct rational homotopy models for classifying spaces of fibrations, giving answers in terms of classical homological functors, namely the Chevalley-Eilenberg and Harrison…

Algebraic Topology · Mathematics 2013-12-13 Andrey Lazarev

We revisit Gersten's $\ell^\infty$-cohomology of groups and spaces, removing the finiteness assumptions required by the original definition while retaining its geometric nature. Mirroring the corresponding results in bounded cohomology, we…

Geometric Topology · Mathematics 2025-10-03 Francesco Milizia

In the paper, notions of relative separability for hypergraphs of models of a theory are defined. Properties of these notions and applications to ordered theories are studied: characterizations of relative separability both in a general…

Logic · Mathematics 2018-02-23 Beibut Kulpeshov , Sergey Sudoplatov

These are expanded notes of four introductory talks on A-infinity algebras, their modules and their derived categories.

Rings and Algebras · Mathematics 2007-05-23 Bernhard Keller

We discuss the notions of resurgence, formalizability, and formation of singularities in the context of partial differential equations. The results show that Ecalle's how analyzability theory extends naturally to PDEs.

Analysis of PDEs · Mathematics 2007-05-23 O. Costin , S. Tanveer

Basis and limitations of singularity theorems for Gravity are examined. As singularity is a critical situation in course of time, study of time paths, in full generality of Equivalence principle, provides two mechanisms to prevent…

General Relativity and Quantum Cosmology · Physics 2007-05-23 K. H. Mariwalla

We give an overview of the fundamental definitions and results concerning hypersurface singularities, defined by convergent power series over an arbitrary real valued field. This approach combines, on the one hand, the classical case of…

Algebraic Geometry · Mathematics 2026-02-18 Gert-Martin Greuel

The spacetime singularity in relativistic cosmology is cancelled by using an additional variable. That is, the singularity-free models for an expanding universe are obtained from general relativity.

General Physics · Physics 2012-04-06 Jae-Hyung Myung

We suggest that for singular rotationally invariant closed string backgrounds which need sources for their support at the origin (in particular, for special plane waves and fundamental strings) certain `trivial' \a'-corrections (which are…

High Energy Physics - Theory · Physics 2009-09-17 A. A. Tseytlin

This paper investigates if a differential graded algebra can have more than one $A_\infty$-structure extending the given differential graded algebra structure. We give a sufficient condition for uniqueness of such an $A_\infty$-structure up…

Algebraic Topology · Mathematics 2014-10-01 Constanze Roitzheim , Sarah Whitehouse

We investigate the distribution of zeros of the partition function of the two- and three-dimensional symmetric $\pm J$ Ising spin glasses on the complex field plane. We use the method to analytically implement the idea of numerical transfer…

Disordered Systems and Neural Networks · Physics 2008-08-04 Yoshiki Matsuda , Hidetoshi Nishimori , Koji Hukushima

We extend the generalized gradient-flow framework of Peletier, Rossi, Savar\'e, and Tse to singular jump processes on abstract metric spaces, moving beyond the translation-invariant kernels considered in $\mathbb{R}^d$ and $\mathbb{T}^d$ in…

Analysis of PDEs · Mathematics 2025-09-24 Jasper Hoeksema , Riccarda Rossi , Oliver Tse

We prove Tsygan's formality conjecture for Hochschild chains of the algebra of functions on an arbitrary smooth manifold M using the Fedosov resolutions proposed in math.QA/0307212 and the formality quasi-isomorphism for Hochschild chains…

Quantum Algebra · Mathematics 2007-05-23 Vasiliy Dolgushev