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In this paper we study cobordism categories consisting of manifolds which are endowed with geometric structure. Examples of such geometric structures include symplectic structures, flat connections on principal bundles, and complex…

Algebraic Topology · Mathematics 2009-06-11 David Ayala

We give complete geometric invariants of cobordisms of framed fold maps. These invariants consist of two types. We take the immersion of the fold singular set into the target manifold together with information about non-triviality of the…

Geometric Topology · Mathematics 2022-12-21 Boldizsar Kalmar

In this paper we study the topology of cobordism categories of manifolds with corners. Specifically, if {Cob}_{d,<k>} is the category whose objets are a fixed dimension d, with corners of codimension less than or equal to k, then we…

Algebraic Topology · Mathematics 2008-11-19 Josh Genauer

A generic smooth map of a closed $2k$-manifold into $(3k-1)$-space has a finite number of cusps ($\Sigma^{1,1}$-singularities). We determine the possible numbers of cusps of such maps. A fold map is a map with singular set consisting of…

Geometric Topology · Mathematics 2007-05-23 Tobias Ekholm , Andras Szucs , Tamas Terpai

Based on Morse theory for the energy functional on path spaces we develop a deformation theory for mapping spaces of spheres into orthogonal groups. This is used to show that these mapping spaces are weakly homotopy equivalent, in a stable…

Algebraic Topology · Mathematics 2021-04-14 Jost-Hinrich Eschenburg , Bernhard Hanke

We use classical results in smoothing theory to extract information about the rational homotopy groups of the space of negatively curved metrics on a high dimensional manifold. It is also shown that smooth M-bundles over spheres equipped…

Geometric Topology · Mathematics 2019-11-27 Mauricio Bustamante , Francis Thomas Farrell , Yi Jiang

We prove that many spaces of positive scalar curvature metrics have the homotopy type of infinite loop spaces. Our result in particular applies to the path component of the round metric inside $\mathcal{R}^+ (S^d)$ if $d \geq 6$. To achieve…

Algebraic Topology · Mathematics 2025-11-24 Johannes Ebert , Oscar Randal-Williams

We study here compact manifolds with positive scalar curvature metrics. We use the relative Yamabe invariant from math.DG/0008138 to define the conformal cobordism relation on the category of such manifolds. We prove that corresponding…

Differential Geometry · Mathematics 2019-08-17 Kazuo Akutagawa , Boris Botvinnik

We consider an entropy-type invariant which measures the polynomial volume growth of submanifolds under the iterates of a map, and we establish sharp uniform lower bounds of this invariant for the following classes of symplectomorphisms of…

Symplectic Geometry · Mathematics 2007-05-23 Urs Frauenfelder , Felix Schlenk

Galatius, Madsen, Tillmann and Weiss have identified the homotopy type of the classifying space of the cobordism category with objects (d-1)-dimensional manifolds embedded in R^\infty. In this paper we apply the techniques of spaces of…

Algebraic Topology · Mathematics 2011-09-23 Oscar Randal-Williams

The homology groups of the automorphism group of a free group are known to stabilize as the number of generators of the free group goes to infinity, and this paper relativizes this result to a family of groups that can be defined in terms…

Geometric Topology · Mathematics 2014-11-11 Allen Hatcher , Nathalie Wahl

For a finite group $G$, we define an equivariant cobordism category $\mathcal{C}_d^G$. Objects of the category are $(d-1)$-dimensional closed smooth $G$-manifolds and morphisms are smooth $d$-dimensional equivariant cobordisms. We identify…

Algebraic Topology · Mathematics 2022-03-25 Gergely Szűcs , Søren Galatius

For each integer q>0 there is a cohomology theory such that the zero cohomology group of a manifold N of dimension n is a certain group of cobordism classes of proper fold maps of manifolds of dimension n+q into N. We prove a splitting…

Geometric Topology · Mathematics 2012-03-06 Rustam Sadykov

Let A be a finite abelian group. We set up an algebraic framework for studying A-equivariant complex-orientable cohomology theories in terms of a suitable kind of equivariant formal groups. We compute the equivariant cohomology of many…

Algebraic Topology · Mathematics 2008-11-14 Neil P. Strickland

Recently the author has introduced cobordism-like modules induced from generic maps whose codimensions are negative. They are generalizations of cobordism modules of manifolds. They have been introduced in generalizing the following theorem…

General Topology · Mathematics 2019-02-05 Naoki Kitazawa

By results of Loeffler and Comezana, the Pontrjagin-Thom map from geometric G-equivariant bordism to homotopy theoretic equivariant bordism is injective for compact abelian G. If G = S^1 x ... x S^1, we prove that the associated fixed point…

Algebraic Topology · Mathematics 2007-05-23 Bernhard Hanke

We provide several results on the existence of metrics of non-negative sectional curvature on vector bundles over certain cohomogeneity one manifolds and homogeneous spaces up to suitable stabilization. Beside explicit constructions of the…

Differential Geometry · Mathematics 2022-05-09 Manuel Amann , David González-Álvaro , Marcus Zibrowius

For a complex projective space the inertia group, the homotopy inertia group and the concordance inertia group are isomorphic. In complex dimension 4n+1, these groups are related to computations in stable cohomotopy. Using stable homotopy…

Algebraic Topology · Mathematics 2018-03-16 Samik Basu , Ramesh Kasilingam

The Pontryagin-Thom construction provides a fundamental link between cobordism groups and the homotopy groups of Thom spectra. Our main result refines this theorem, providing a more explicit geometric interpretation of the homotopy groups…

Algebraic Topology · Mathematics 2026-03-13 Naoki Kuroda

Denote by $\mathcal{Z}_5((\mathbb{Z}_2)^3)$ the group, which is also a vector space over $\mathbb{Z}_2$, generated by equivariant unoriented bordism classes of all five-dimensional closed smooth manifolds with effective smooth…

Algebraic Topology · Mathematics 2025-04-15 Yuanxin Guan , Zhi Lü