314 research outputs found

    Protein folding disorders: Toward a basic biological paradigm

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    Mechanistic 'physics' models of protein folding fail to account for the observed spectrum of protein folding and aggregation disorders, suggesting that a more appropriately biological paradigm will be needed for understanding the etiology, prevention, and treatment of these diseases

    Some Examples of Minimal Groupoids on a Finite Set (Algebraic System, Logic, Language and Related Areas in Computer Science)

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    A minimal clone is an atom in the lattice of clones. The classification of minimal clones on a finite set still remains unsolved. A minimal groupoid is a minimal clone generated by a binary idempotent function. In this paper we report some examples of minimal groupoids generated by binary functions which resemble projections

    HOMFLYPT Skein Theory, String Topology and 2-Categories

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    We show that relations in Homflypt type skein theory of an oriented 33-manifold MM are induced from a 22-groupoid defined from the fundamental 22-groupoid of a space of singular links in MM. The module relations are defined by homomorphisms related to string topology. They appear from a representation of the groupoid into free modules on a set of model objects. The construction on the fundamental 22-groupoid is defined by the singularity stratification and relates Vassiliev and skein theory. Several explicit properties are discussed, and some implications for skein modules are derived.Comment: 55 pages, 1 figur

    Endomorphisms of Koszul complexes: formality and application to deformation theory

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    We study the differential graded Lie algebra of endomorphisms of the Koszul resolution of a regular sequence on a unitary commutative K-algebra R and we prove that it is homotopy abelian over K but not over R (except trivial cases). We apply this result to prove an annihilation theorem for obstructions of (derived) deformations of locally complete intersection ideal sheaves on projective schemes

    An introduction to moduli stacks, with a view towards Higgs bundles on algebraic curves

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    This article is based in part on lecture notes prepared for the summer school "The Geometry, Topology and Physics of Moduli Spaces of Higgs Bundles" at the Institute for Mathematical Sciences at the National University of Singapore in July of 2014. The aim is to provide a brief introduction to algebraic stacks, and then to give several constructions of the moduli stack of Higgs bundles on algebraic curves. The first construction is via a "bootstrap" method from the algebraic stack of vector bundles on an algebraic curve. This construction is motivated in part by Nitsure's GIT construction of a projective moduli space of semi-stable Higgs bundles, and we describe the relationship between Nitsure's moduli space and the algebraic stacks constructed here. The third approach is via deformation theory, where we directly construct the stack of Higgs bundles using Artin's criterion.Comment: 145 pages, AMS LaTeX, to appear in the NUS IMS Lecture Note Series on The Geometry, Topology, and Physics of Moduli Spaces of Higgs Bundle
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