Reduced Fusion Systems over 2-Groups of Sectional Rank at Most 4

Reduced Fusion Systems over 2-Groups of Sectional Rank at Most 4 PDF Author: Bob Oliver
Publisher: American Mathematical Soc.
ISBN: 1470415488
Category : Mathematics
Languages : en
Pages : 112

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Book Description
The author classifies all reduced, indecomposable fusion systems over finite -groups of sectional rank at most . The resulting list is very similar to that by Gorenstein and Harada of all simple groups of sectional -rank at most . But this method of proof is very different from theirs, and is based on an analysis of the essential subgroups which can occur in the fusion systems.

Reduced Fusion Systems over 2-Groups of Sectional Rank at Most 4

Reduced Fusion Systems over 2-Groups of Sectional Rank at Most 4 PDF Author: Bob Oliver
Publisher: American Mathematical Soc.
ISBN: 1470415488
Category : Mathematics
Languages : en
Pages : 112

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Book Description
The author classifies all reduced, indecomposable fusion systems over finite -groups of sectional rank at most . The resulting list is very similar to that by Gorenstein and Harada of all simple groups of sectional -rank at most . But this method of proof is very different from theirs, and is based on an analysis of the essential subgroups which can occur in the fusion systems.

Nil Bohr-Sets and Almost Automorphy of Higher Order

Nil Bohr-Sets and Almost Automorphy of Higher Order PDF Author: Wen Huang
Publisher: American Mathematical Soc.
ISBN: 147041872X
Category : Mathematics
Languages : en
Pages : 98

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Book Description
Two closely related topics, higher order Bohr sets and higher order almost automorphy, are investigated in this paper. Both of them are related to nilsystems. In the first part, the problem which can be viewed as the higher order version of an old question concerning Bohr sets is studied: for any d∈N does the collection of {n∈Z:S∩(S−n)∩…∩(S−dn)≠∅} with S syndetic coincide with that of Nild Bohr0 -sets? In the second part, the notion of d -step almost automorphic systems with d∈N∪{∞} is introduced and investigated, which is the generalization of the classical almost automorphic ones.

Monoidal Categories and the Gerstenhaber Bracket in Hochschild Cohomology

Monoidal Categories and the Gerstenhaber Bracket in Hochschild Cohomology PDF Author: Reiner Hermann:
Publisher: American Mathematical Soc.
ISBN: 1470419955
Category : Mathematics
Languages : en
Pages : 158

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Book Description
In this monograph, the author extends S. Schwede's exact sequence interpretation of the Gerstenhaber bracket in Hochschild cohomology to certain exact and monoidal categories. Therefore the author establishes an explicit description of an isomorphism by A. Neeman and V. Retakh, which links Ext-groups with fundamental groups of categories of extensions and relies on expressing the fundamental group of a (small) category by means of the associated Quillen groupoid. As a main result, the author shows that his construction behaves well with respect to structure preserving functors between exact monoidal categories. The author uses his main result to conclude, that the graded Lie bracket in Hochschild cohomology is an invariant under Morita equivalence. For quasi-triangular bialgebras, he further determines a significant part of the Lie bracket's kernel, and thereby proves a conjecture by L. Menichi. Along the way, the author introduces n-extension closed and entirely extension closed subcategories of abelian categories, and studies some of their properties.

Carleman Estimates, Observability Inequalities and Null Controllability for Interior Degenerate Nonsmooth Parabolic Equations

Carleman Estimates, Observability Inequalities and Null Controllability for Interior Degenerate Nonsmooth Parabolic Equations PDF Author: Genni Fragnelli
Publisher: American Mathematical Soc.
ISBN: 1470419548
Category : Mathematics
Languages : en
Pages : 96

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Book Description
The authors consider a parabolic problem with degeneracy in the interior of the spatial domain, and they focus on observability results through Carleman estimates for the associated adjoint problem. The novelties of the present paper are two. First, the coefficient of the leading operator only belongs to a Sobolev space. Second, the degeneracy point is allowed to lie even in the interior of the control region, so that no previous result can be adapted to this situation; however, different cases can be handled, and new controllability results are established as a consequence.

Igusa's $p$-Adic Local Zeta Function and the Monodromy Conjecture for Non-Degenerate Surface Singularities

Igusa's $p$-Adic Local Zeta Function and the Monodromy Conjecture for Non-Degenerate Surface Singularities PDF Author: Bart Bories
Publisher: American Mathematical Soc.
ISBN: 147041841X
Category : Mathematics
Languages : en
Pages : 146

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Book Description
In 2011 Lemahieu and Van Proeyen proved the Monodromy Conjecture for the local topological zeta function of a non-degenerate surface singularity. The authors start from their work and obtain the same result for Igusa's p-adic and the motivic zeta function. In the p-adic case, this is, for a polynomial f∈Z[x,y,z] satisfying f(0,0,0)=0 and non-degenerate with respect to its Newton polyhedron, we show that every pole of the local p-adic zeta function of f induces an eigenvalue of the local monodromy of f at some point of f−1(0)⊂C3 close to the origin. Essentially the entire paper is dedicated to proving that, for f as above, certain candidate poles of Igusa's p-adic zeta function of f, arising from so-called B1-facets of the Newton polyhedron of f, are actually not poles. This turns out to be much harder than in the topological setting. The combinatorial proof is preceded by a study of the integral points in three-dimensional fundamental parallelepipeds. Together with the work of Lemahieu and Van Proeyen, this main result leads to the Monodromy Conjecture for the p-adic and motivic zeta function of a non-degenerate surface singularity.

Real Non-Abelian Mixed Hodge Structures for Quasi-Projective Varieties: Formality and Splitting

Real Non-Abelian Mixed Hodge Structures for Quasi-Projective Varieties: Formality and Splitting PDF Author: J. P. Pridham
Publisher: American Mathematical Soc.
ISBN: 1470419815
Category : Mathematics
Languages : en
Pages : 190

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Book Description
The author defines and constructs mixed Hodge structures on real schematic homotopy types of complex quasi-projective varieties, giving mixed Hodge structures on their homotopy groups and pro-algebraic fundamental groups. The author also shows that these split on tensoring with the ring R[x] equipped with the Hodge filtration given by powers of (x−i), giving new results even for simply connected varieties. The mixed Hodge structures can thus be recovered from the Gysin spectral sequence of cohomology groups of local systems, together with the monodromy action at the Archimedean place. As the basepoint varies, these structures all become real variations of mixed Hodge structure.

Layer Potentials and Boundary-Value Problems for Second Order Elliptic Operators with Data in Besov Spaces

Layer Potentials and Boundary-Value Problems for Second Order Elliptic Operators with Data in Besov Spaces PDF Author: Ariel Barton:
Publisher: American Mathematical Soc.
ISBN: 1470419890
Category : Mathematics
Languages : en
Pages : 122

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Book Description
This monograph presents a comprehensive treatment of second order divergence form elliptic operators with bounded measurable t-independent coefficients in spaces of fractional smoothness, in Besov and weighted Lp classes. The authors establish: (1) Mapping properties for the double and single layer potentials, as well as the Newton potential; (2) Extrapolation-type solvability results: the fact that solvability of the Dirichlet or Neumann boundary value problem at any given Lp space automatically assures their solvability in an extended range of Besov spaces; (3) Well-posedness for the non-homogeneous boundary value problems. In particular, the authors prove well-posedness of the non-homogeneous Dirichlet problem with data in Besov spaces for operators with real, not necessarily symmetric, coefficients.

An Inverse Spectral Problem Related to the Geng-Xue Two-Component Peakon Equation

An Inverse Spectral Problem Related to the Geng-Xue Two-Component Peakon Equation PDF Author: Hans Lundmark
Publisher: American Mathematical Soc.
ISBN: 1470420260
Category : Mathematics
Languages : en
Pages : 102

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Book Description
The authors solve a spectral and an inverse spectral problem arising in the computation of peakon solutions to the two-component PDE derived by Geng and Xue as a generalization of the Novikov and Degasperis-Procesi equations. Like the spectral problems for those equations, this one is of a "discrete cubic string" type, but presents some interesting novel features.

Hyperbolically Embedded Subgroups and Rotating Families in Groups Acting on Hyperbolic Spaces

Hyperbolically Embedded Subgroups and Rotating Families in Groups Acting on Hyperbolic Spaces PDF Author: F. Dahmani
Publisher: American Mathematical Soc.
ISBN: 1470421941
Category : Mathematics
Languages : en
Pages : 164

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Book Description
he authors introduce and study the notions of hyperbolically embedded and very rotating families of subgroups. The former notion can be thought of as a generalization of the peripheral structure of a relatively hyperbolic group, while the latter one provides a natural framework for developing a geometric version of small cancellation theory. Examples of such families naturally occur in groups acting on hyperbolic spaces including hyperbolic and relatively hyperbolic groups, mapping class groups, , and the Cremona group. Other examples can be found among groups acting geometrically on spaces, fundamental groups of graphs of groups, etc. The authors obtain a number of general results about rotating families and hyperbolically embedded subgroups; although their technique applies to a wide class of groups, it is capable of producing new results even for well-studied particular classes. For instance, the authors solve two open problems about mapping class groups, and obtain some results which are new even for relatively hyperbolic groups.

Locally Analytic Vectors in Representations of Locally $p$-adic Analytic Groups

Locally Analytic Vectors in Representations of Locally $p$-adic Analytic Groups PDF Author: Matthew J. Emerton
Publisher: American Mathematical Soc.
ISBN: 0821875620
Category : Mathematics
Languages : en
Pages : 168

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Book Description
The goal of this memoir is to provide the foundations for the locally analytic representation theory that is required in three of the author's other papers on this topic. In the course of writing those papers the author found it useful to adopt a particular point of view on locally analytic representation theory: namely, regarding a locally analytic representation as being the inductive limit of its subspaces of analytic vectors (of various “radii of analyticity”). The author uses the analysis of these subspaces as one of the basic tools in his study of such representations. Thus in this memoir he presents a development of locally analytic representation theory built around this point of view. The author has made a deliberate effort to keep the exposition reasonably self-contained and hopes that this will be of some benefit to the reader.