Geodesics, Retracts, and the Norm-Preserving Extension Property in the Symmetrized Bidisc

Geodesics, Retracts, and the Norm-Preserving Extension Property in the Symmetrized Bidisc PDF Author: Jim Agler
Publisher: American Mathematical Soc.
ISBN: 1470435497
Category : Mathematics
Languages : en
Pages : 122

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Book Description
A set V in a domain U in Cn has the norm-preserving extension property if every bounded holomorphic function on V has a holomorphic extension to U with the same supremum norm. We prove that an algebraic subset of the symmetrized bidisc

Geodesics, Retracts, and the Norm-Preserving Extension Property in the Symmetrized Bidisc

Geodesics, Retracts, and the Norm-Preserving Extension Property in the Symmetrized Bidisc PDF Author: Jim Agler
Publisher: American Mathematical Soc.
ISBN: 1470435497
Category : Mathematics
Languages : en
Pages : 122

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Book Description
A set V in a domain U in Cn has the norm-preserving extension property if every bounded holomorphic function on V has a holomorphic extension to U with the same supremum norm. We prove that an algebraic subset of the symmetrized bidisc

Algebraic Geometry over C∞-Rings

Algebraic Geometry over C∞-Rings PDF Author: Dominic Joyce
Publisher: American Mathematical Soc.
ISBN: 1470436450
Category : Mathematics
Languages : en
Pages : 152

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Book Description
If X is a manifold then the R-algebra C∞(X) of smooth functions c:X→R is a C∞-ring. That is, for each smooth function f:Rn→R there is an n-fold operation Φf:C∞(X)n→C∞(X) acting by Φf:(c1,…,cn)↦f(c1,…,cn), and these operations Φf satisfy many natural identities. Thus, C∞(X) actually has a far richer structure than the obvious R-algebra structure. The author explains the foundations of a version of algebraic geometry in which rings or algebras are replaced by C∞-rings. As schemes are the basic objects in algebraic geometry, the new basic objects are C∞-schemes, a category of geometric objects which generalize manifolds and whose morphisms generalize smooth maps. The author also studies quasicoherent sheaves on C∞-schemes, and C∞-stacks, in particular Deligne-Mumford C∞-stacks, a 2-category of geometric objects generalizing orbifolds. Many of these ideas are not new: C∞-rings and C∞ -schemes have long been part of synthetic differential geometry. But the author develops them in new directions. In earlier publications, the author used these tools to define d-manifolds and d-orbifolds, “derived” versions of manifolds and orbifolds related to Spivak's “derived manifolds”.

Compact Quotients of Cahen-Wallach Spaces

Compact Quotients of Cahen-Wallach Spaces PDF Author: Ines Kath
Publisher: American Mathematical Soc.
ISBN: 1470441039
Category : Education
Languages : en
Pages : 96

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Book Description
Indecomposable symmetric Lorentzian manifolds of non-constant curvature are called Cahen-Wallach spaces. Their isometry classes are described by continuous families of real parameters. The authors derive necessary and sufficient conditions for the existence of compact quotients of Cahen-Wallach spaces in terms of these parameters.

Nonlinear Diffusion Equations and Curvature Conditions in Metric Measure Spaces

Nonlinear Diffusion Equations and Curvature Conditions in Metric Measure Spaces PDF Author: Luigi Ambrosio
Publisher: American Mathematical Soc.
ISBN: 1470439131
Category : Education
Languages : en
Pages : 134

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Book Description
The aim of this paper is to provide new characterizations of the curvature dimension condition in the context of metric measure spaces (X,d,m). On the geometric side, the authors' new approach takes into account suitable weighted action functionals which provide the natural modulus of K-convexity when one investigates the convexity properties of N-dimensional entropies. On the side of diffusion semigroups and evolution variational inequalities, the authors' new approach uses the nonlinear diffusion semigroup induced by the N-dimensional entropy, in place of the heat flow. Under suitable assumptions (most notably the quadraticity of Cheeger's energy relative to the metric measure structure) both approaches are shown to be equivalent to the strong CD∗(K,N) condition of Bacher-Sturm.

Quasi-periodic Standing Wave Solutions of Gravity-Capillary Water Waves

Quasi-periodic Standing Wave Solutions of Gravity-Capillary Water Waves PDF Author: Massimiliano Berti
Publisher: American Mathematical Soc.
ISBN: 1470440695
Category : Education
Languages : en
Pages : 184

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Book Description
The authors prove the existence and the linear stability of small amplitude time quasi-periodic standing wave solutions (i.e. periodic and even in the space variable x) of a 2-dimensional ocean with infinite depth under the action of gravity and surface tension. Such an existence result is obtained for all the values of the surface tension belonging to a Borel set of asymptotically full Lebesgue measure.

Automorphisms of Fusion Systems of Finite Simple Groups of Lie Type

Automorphisms of Fusion Systems of Finite Simple Groups of Lie Type PDF Author: Carles Broto
Publisher: American Mathematical Soc.
ISBN: 1470437724
Category : Education
Languages : en
Pages : 176

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Book Description
For a finite group G of Lie type and a prime p, the authors compare the automorphism groups of the fusion and linking systems of G at p with the automorphism group of G itself. When p is the defining characteristic of G, they are all isomorphic, with a very short list of exceptions. When p is different from the defining characteristic, the situation is much more complex but can always be reduced to a case where the natural map from Out(G) to outer automorphisms of the fusion or linking system is split surjective. This work is motivated in part by questions involving extending the local structure of a group by a group of automorphisms, and in part by wanting to describe self homotopy equivalences of BG∧p in terms of Out(G).

Hodge Ideals

Hodge Ideals PDF Author: Mircea Mustaţă
Publisher: American Mathematical Soc.
ISBN: 1470437813
Category : Education
Languages : en
Pages : 92

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Book Description
The authors use methods from birational geometry to study the Hodge filtration on the localization along a hypersurface. This filtration leads to a sequence of ideal sheaves, called Hodge ideals, the first of which is a multiplier ideal. They analyze their local and global properties, and use them for applications related to the singularities and Hodge theory of hypersurfaces and their complements.

A Local Relative Trace Formula for the Ginzburg-Rallis Model: The Geometric Side

A Local Relative Trace Formula for the Ginzburg-Rallis Model: The Geometric Side PDF Author: Chen Wan
Publisher: American Mathematical Soc.
ISBN: 1470436868
Category : Education
Languages : en
Pages : 102

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Book Description
Following the method developed by Waldspurger and Beuzart-Plessis in their proofs of the local Gan-Gross-Prasad conjecture, the author is able to prove the geometric side of a local relative trace formula for the Ginzburg-Rallis model. Then by applying such formula, the author proves a multiplicity formula of the Ginzburg-Rallis model for the supercuspidal representations. Using that multiplicity formula, the author proves the multiplicity one theorem for the Ginzburg-Rallis model over Vogan packets in the supercuspidal case.

On the Stability of Type I Blow Up for the Energy Super Critical Heat Equation

On the Stability of Type I Blow Up for the Energy Super Critical Heat Equation PDF Author: Charles Collot
Publisher: American Mathematical Soc.
ISBN: 1470436264
Category : Mathematics
Languages : en
Pages : 110

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Book Description
The authors consider the energy super critical semilinear heat equation The authors first revisit the construction of radially symmetric self similar solutions performed through an ode approach and propose a bifurcation type argument which allows for a sharp control of the spectrum of the corresponding linearized operator in suitable weighted spaces. They then show how the sole knowledge of this spectral gap in weighted spaces implies the finite codimensional nonradial stability of these solutions for smooth well localized initial data using energy bounds. The whole scheme draws a route map for the derivation of the existence and stability of self-similar blow up in nonradial energy super critical settings.

Time-Like Graphical Models

Time-Like Graphical Models PDF Author: Tvrtko Tadić
Publisher: American Mathematical Soc.
ISBN: 147043685X
Category : Education
Languages : en
Pages : 184

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Book Description
The author studies continuous processes indexed by a special family of graphs. Processes indexed by vertices of graphs are known as probabilistic graphical models. In 2011, Burdzy and Pal proposed a continuous version of graphical models indexed by graphs with an embedded time structure— so-called time-like graphs. The author extends the notion of time-like graphs and finds properties of processes indexed by them. In particular, the author solves the conjecture of uniqueness of the distribution for the process indexed by graphs with infinite number of vertices. The author provides a new result showing the stochastic heat equation as a limit of the sequence of natural Brownian motions on time-like graphs. In addition, the author's treatment of time-like graphical models reveals connections to Markov random fields, martingales indexed by directed sets and branching Markov processes.