Journal of Topology最新文献

A representation of a finitely generated group into the projective general linear group is called convex co-compact if it has finite kernel and its image acts convex co-compactly on a properly convex domain in real projective space. We prove that the fundamental group of a closed irreducible orientable 3-manifold can admit such a representation only when the manifold is geometric (with Euclidean, Hyperbolic or Euclidean $�\times$ Hyperbolic geometry) or when every component in the geometric decomposition is hyperbolic. In each case, we describe the structure of such examples.

We show that Koszul duality for operads in $��(�\mathrm{Top}�,�\times �)�$ can be expressed via generalized Thom complexes. As an application, we prove the Koszul self-duality of the right module $�E_M$ associated to a framed manifold $�M$. We discuss implications for factorization homology, embedding calculus, and confirm an old conjecture of Ching on the relation of Goodwillie calculus to manifold calculus.

Let $�L$ be an exact Lagrangian submanifold of a cotangent bundle $��T^{\ast }�M�$, asymptotic to a Legendrian submanifold $��\Lambda �\subset �T^{\infty }�M�$. We study a locally constant sheaf of $�\infty$-categories on $�L$, called the sheaf of brane structures or $�{\mathrm{Brane}}_L$. Its fiber is the $�\infty$-category of spectra, and we construct a Hamiltonian invariant, fully faithful functor from $��\Gamma �(�L�,�{\mathrm{Brane}}_L�)�$ to the $�\infty$-category of sheaves of spectra on $�M$ with singular support in $�\Lambda$.

We provide a construction of equivariant Lagrangian Floer homology $��H�F_G��(�L_0�,�L_1�)��$, for a compact Lie group $�G$ acting on a symplectic manifold $�M$ in a Hamiltonian fashion, and a pair of $�G$-Lagrangian submanifolds $��L_0�,�L_1�\subset �M�$. We do so by using symplectic homotopy quotients involving cotangent bundles of an approximation of $��E�G�$. Our construction relies on Wehrheim and Woodward's theory of quilts, and the telescope construction. We show that these groups are independent of the auxiliary choices involved in their construction, and are $��H^{\ast }��\left(�B�G�\right)��$-bimodules. In the case w

Given a class of embeddings into a contact or a symplectic manifold, we give a sufficient condition, that we call isocontact or isosymplectic realization, for this class to satisfy a general $�h$-principle. The flexibility follows from the $�h$-principles for isocontact and isosymplectic embeddings, it provides a framework for classical results, and we give two new applications. Our main result is that embeddings transverse to a contact structure satisfy a full $�h$-principle in two cases: if the complement of the embedding is overtwisted, or when the intersection of the image of the formal derivative with the contact structure is strictly contained in a proper symplectic subbundle. We illustrate the general framework on symplectic manifolds by studying the universality of Hamiltonian dynamics on regular level sets via a class of embeddings.

We study several aspects of fillings for links of general isolated quotient singularities using Floer theory, including co-fillings, Weinstein fillings, strong fillings, exact fillings and exact orbifold fillings, focusing on the non-existence of exact fillings of contact links of isolated terminal quotient singularities. We provide an extensive list of isolated terminal quotient singularities whose contact links are not exactly fillable, including $��C^n�/��(�Z�/�2�)��$ for $��n�⩾�3�$, which settles a conjecture of Eliashberg, quotient singularities from general cyclic group actions and finite subgroups of $��S�U�\left(�2�\right)�$, and all terminal quotient singularities in complex dimension 3. We also obtain uniqueness of the orbifold diffeomorphism type of exact orbifold fillings of contact links of some isolated terminal quotient singularities.

For a compact subset $�K$ of a closed symplectic manifold $��(�M�,�\omega �)�$, we prove that $�K$ is heavy if and only if its relative symplectic cohomology over the Novikov field is nonzero. As an application, we show that if two compact sets are not heavy and Poisson commuting, then their union is also not heavy. A discussion on superheaviness together with some partial results is also included.

We calculate the rational cohomology of the classifying space of the diffeomorphism group of the manifolds $��U_{�g�,�1�}^n�:�=�{\#}^g��(�S^n�\times �S^{�n�+�1�}�)��\setminus �\mathrm{int}��\left(�D^{�2�n�+�1�}�\right)��$, for large $�g$ and $�n$, up to degree $��n�-�3�$. The answer is that it is a free graded commutative algebra on an appropriate set of Miller–Morita–Mumford classes. Our proof goes through the classical three-step procedure: (a) compute the cohomology of the homotopy automorphisms, (b) use surgery to compare this to block diffeomorphisms, and (c) use pseudoisotopy theory and algebraic $�K$

In this article, we study the iteration of Cox rings of klt singularities (and Fano varieties) from a topological perspective. Given a klt singularity $��(�X�,�\Delta �;�x�)�$, we define the iteration of Cox rings of $��(�X�,�\Delta �;�x�)�$. The first result of this article is that the iteration of Cox rings $��{\mathrm{Cox}}^{�\left(�k�\right)�}��(�X�,�\Delta �;�x�)��$ of a klt singularity stabilizes for $�k$ large enough. The second result is a boundedness one, we prove that for an $�n$-dimensional klt singularity $��(�X�,�\Delta �;�x�)�$, the iteration of Cox rings stabilizes for $��k�⩾�c�\left(�n�\right)�$, where $��c�(�n�$

Let $��\chi �\in �H^1��(�{\Sigma }_h�,�Q�)��$ denote a rational cohomology class, and let $�H_{\chi }$ denote its Hodge norm. We recover the result that $�H_{\chi }$ is a plurisubharmonic function on the Teichmüller space $�T_h$, and characterize complex directions along which the complex Hessian of $�H_{\chi }$ vanishes. Moreover, we find examples of $��\chi �\in �H^1��(�{\Sigma }_h�,�Q�)��$ such that $�H_{\chi }$ is not strictly plurisubharmonic. As part of this construction, we find an unbranched covering $��\pi �:�{\Sigma }_{}$