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Related papers: On k-decomposability of positive maps

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We use Gromov's K--area to define a generalized homology theory on compact smooth manifolds. In fact, this theory collects obstructions to the enlargeability of the manifold and its nontrivial submanifolds. Moreover, using the K--area…

Differential Geometry · Mathematics 2010-08-03 Mario Listing

The moduli spaces refered to are topological spaces whose path components parametrize homotopy types. Such objects have been studied in two separate contexts: rational homotopy types, in the work of several authors in the late 1970's; and…

Algebraic Topology · Mathematics 2007-05-23 David Blanc

We give a new, and hopefully more easily understandable, structural proof of the decomposition of a $k$-valued transducer into $k$ unambiguous functional ones, a result established by A. Weber in 1996. Our construction is based on a…

Information Theory · Computer Science 2008-02-21 Jacques Sakarovitch , Rodrigo De Souza

Let $K$ be a field, let $X$ be a connected smooth $K$-scheme and let $G,H$ be two smooth connected $K$-group schemes. Given $Y \to X$ a $G$-torsor and $Z \to Y$ an $H$-torsor, we study whether one can find an extension $E$ of $G$ by $H$ so…

Algebraic Geometry · Mathematics 2023-06-02 Mathieu Florence , Diego Izquierdo , Giancarlo Lucchini Arteche

Let E be a cyclic extension of pth-power degree of a field F of characteristic p. For all m, s in N, we determine K_mE/p^sK_mE as a (Z/p^sZ)[Gal(E/F)]-module. We also provide examples of extensions for which all of the possible nonzero…

Number Theory · Mathematics 2008-06-26 Jan Minac , Andrew Schultz , John Swallow

A harmonic map from a Riemannian manifold into a Grassmannian manifold is characterized by a vector bundle, a space of sections of this bundle and a Laplace operator. We apply our main theorem, itself a generalization of a Theorem of…

Differential Geometry · Mathematics 2014-08-08 Yasuyuki Nagatomo

Let G be a finite group scheme over an algebraically closed field of positive characteristic. Assume further that the connected component of G is unipotent. It is shown that the projectivity of a rational G-module can be detected on a…

Representation Theory · Mathematics 2019-09-25 Christopher P. Bendel

We introduce structured decompositions, category-theoretic structures which simultaneously generalize notions from graph theory (including treewidth, layered treewidth, co-treewidth, graph decomposition width, tree independence number,…

Category Theory · Mathematics 2025-05-21 Benjamin Merlin Bumpus , Zoltan A. Kocsis , Jade Edenstar Master , Emilio Minichiello

We apply Hilbert module methods to show that normal completely positive maps admit weak tensor dilations. Appealing to a duality between weak tensor dilations and extensions of CP-maps, we get an existence proof for certain extensions. We…

Operator Algebras · Mathematics 2007-05-23 Rolf Gohm , Michael Skeide

We give several versions of local and global inverse mapping theorem for tame non necessarily smooth, mappings. Here tame mapping means a mapping which is subanalytic or, more generally, definable in some o-minimal structure. Our sufficient…

Geometric Topology · Mathematics 2007-12-18 Toshizumi Fukui , Krzysztof Kurdyka , Laurentiu Paunescu

We survey two new compactification methods for the KSBA moduli space of general type surfaces so that both of them admit a perfect obstruction theory. Virtual fundamental classes exist on these two moduli spaces, and tautological invariants…

Algebraic Geometry · Mathematics 2026-05-20 Yunfeng Jiang

We give a motivated introduction to the theory of perverse sheaves, culminating in the Decomposition Theorem of Beilinson, Bernstein, Deligne and Gabber. A goal of this survey is to show how the theory develops naturally from classical…

Algebraic Geometry · Mathematics 2009-04-16 Mark Andrea de Cataldo , Luca Migliorini

We outline a new approach to the characterization as well as to the classification of positive maps. This approach is based on the facial structures of the set of states and of the cone of positive maps. In particular, the equivalence…

Quantum Physics · Physics 2007-05-23 Wladyslaw Adam Majewski

Motivated by applications in moduli theory, we introduce a flexible and powerful language for expressing lower bounds on relative dimension of morphisms of schemes, and more generally of algebraic stacks. We show that the theory is robust…

Algebraic Geometry · Mathematics 2013-05-29 Brian Osserman

In the context of complex algebraic varieties, the decomposition theorem for semi-small maps provides a decomposition of the direct image of the constant sheaf. In this work, we develop a decomposition theorem for branched coverings of…

Algebraic Topology · Mathematics 2026-03-02 Shahryar Ghaed Sharaf

An order-theoretic generalization of Seymour relations describing the connection between the set-theoretic blocker, deletion, and contraction maps on clutters, is presented.

Combinatorics · Mathematics 2007-05-23 Andrey O. Matveev

By employing polynomial-reduced KP integrability, combined with the string equation, this work establishes explicit relationships between the generalized Kontsevich model, the topological recursion of the spectral curve, and the geometry of…

Mathematical Physics · Physics 2026-05-05 Shuai Guo , Ce Ji , Chenglang Yang , Qingsheng Zhang

We give $\operatorname{CMSO}$-transductions that, given a graph $G$, output its modular decomposition, its split decomposition and its bi-join decomposition. This improves results by Courcelle [Logical Methods in Computer Science, 2006] who…

Logic in Computer Science · Computer Science 2026-05-12 Rutger Campbell , Bruno Guillon , Mamadou Moustapha Kanté , Eun Jung Kim , Noleen Köhler

We describe recent work on positive descriptions of the structure constants of the cohomology of homogeneous spaces such as the Grassmannian, by degenerations and related methods. We give various extensions of these rules, some new and…

Algebraic Geometry · Mathematics 2007-05-23 Izzet Coskun , Ravi Vakil

We present a definition of a (super)-modular functor which includes certain interesting cases that previous definitions do not allow. We also introduce a notion of topological twisting of a modular functor, and construct formally a…

K-Theory and Homology · Mathematics 2018-01-09 Igor Kriz , Luhang Lai