Erdos Space and Homeomorphism Groups of Manifolds

Erdos Space and Homeomorphism Groups of Manifolds
Author: Jan Jakobus Dijkstra
Publisher: American Mathematical Soc.
Total Pages: 76
Release: 2010
Genre: Mathematics
ISBN: 0821846353

Let M be either a topological manifold, a Hilbert cube manifold, or a Menger manifold and let D be an arbitrary countable dense subset of M. Consider the topological group H(M,D) which consists of all autohomeomorphisms of M that map D onto itself equipped with the compact-open topology. We present a complete solution to the topological classification problem for H(M,D) as follows. If M is a one-dimensional topological manifold, then we proved in an earlier paper that H(M,D) is homeomorphic to Qω, the countable power of the space of rational numbers. In all other cases we find in this paper that H(M,D) is homeomorphic to the famed Erdős space E E, which consists of the vectors in Hilbert space l2 with rational coordinates. We obtain the second result by developing topological characterizations of Erdős space.

Hardy Spaces Associated to Non-Negative Self-Adjoint Operators Satisfying Davies-Gaffney Estimates

Hardy Spaces Associated to Non-Negative Self-Adjoint Operators Satisfying Davies-Gaffney Estimates
Author: Steve Hofmann
Publisher: American Mathematical Soc.
Total Pages: 91
Release: 2011
Genre: Mathematics
ISBN: 0821852388

Let $X$ be a metric space with doubling measure, and $L$ be a non-negative, self-adjoint operator satisfying Davies-Gaffney bounds on $L^2(X)$. In this article the authors present a theory of Hardy and BMO spaces associated to $L$, including an atomic (or molecular) decomposition, square function characterization, and duality of Hardy and BMO spaces. Further specializing to the case that $L$ is a Schrodinger operator on $\mathbb{R}^n$ with a non-negative, locally integrable potential, the authors establish additional characterizations of such Hardy spaces in terms of maximal functions. Finally, they define Hardy spaces $H^p_L(X)$ for $p>1$, which may or may not coincide with the space $L^p(X)$, and show that they interpolate with $H^1_L(X)$ spaces by the complex method.

Differential Forms on Wasserstein Space and Infinite-Dimensional Hamiltonian Systems

Differential Forms on Wasserstein Space and Infinite-Dimensional Hamiltonian Systems
Author: Wilfrid Gangbo
Publisher: American Mathematical Soc.
Total Pages: 90
Release: 2010
Genre: Mathematics
ISBN: 0821849395

Let $\mathcal{M}$ denote the space of probability measures on $\mathbb{R}^D$ endowed with the Wasserstein metric. A differential calculus for a certain class of absolutely continuous curves in $\mathcal{M}$ was introduced by Ambrosio, Gigli, and Savare. In this paper the authors develop a calculus for the corresponding class of differential forms on $\mathcal{M}$. In particular they prove an analogue of Green's theorem for 1-forms and show that the corresponding first cohomology group, in the sense of de Rham, vanishes. For $D=2d$ the authors then define a symplectic distribution on $\mathcal{M}$ in terms of this calculus, thus obtaining a rigorous framework for the notion of Hamiltonian systems as introduced by Ambrosio and Gangbo. Throughout the paper the authors emphasize the geometric viewpoint and the role played by certain diffeomorphism groups of $\mathbb{R}^D$.

Recent Progress in General Topology III

Recent Progress in General Topology III
Author: K.P. Hart
Publisher: Springer Science & Business Media
Total Pages: 898
Release: 2013-12-11
Genre: Mathematics
ISBN: 946239024X

The book presents surveys describing recent developments in most of the primary subfields of General Topology, and its applications to Algebra and Analysis during the last decade, following the previous editions (North Holland, 1992 and 2002). The book was prepared in connection with the Prague Topological Symposium, held in 2011. During the last 10 years the focus in General Topology changed and therefore the selection of topics differs from that chosen in 2002. The following areas experienced significant developments: Fractals, Coarse Geometry/Topology, Dimension Theory, Set Theoretic Topology and Dynamical Systems.

Axes in Outer Space

Axes in Outer Space
Author: Michael Handel
Publisher: American Mathematical Soc.
Total Pages: 117
Release: 2011
Genre: Mathematics
ISBN: 0821869272

"September 2011, volume 213, number 1004 (end of volume)."

The Internally 4-Connected Binary Matroids with No $M(K_{3,3})$-Minor

The Internally 4-Connected Binary Matroids with No $M(K_{3,3})$-Minor
Author: Dillon Mayhew
Publisher: American Mathematical Soc.
Total Pages: 110
Release: 2010
Genre: Mathematics
ISBN: 0821848267

The authors give a characterization of the internally $4$-connected binary matroids that have no minor isomorphic to $M(K_{3,3})$. Any such matroid is either cographic, or is isomorphic to a particular single-element extension of the bond matroid of a cubic or quartic Mobius ladder, or is isomorphic to one of eighteen sporadic matroids.

Affine Insertion and Pieri Rules for the Affine Grassmannian

Affine Insertion and Pieri Rules for the Affine Grassmannian
Author: Thomas Lam
Publisher: American Mathematical Soc.
Total Pages: 103
Release: 2010
Genre: Mathematics
ISBN: 0821846582

The authors study combinatorial aspects of the Schubert calculus of the affine Grassmannian ${\rm Gr}$ associated with $SL(n,\mathbb{C})$.Their main results are: Pieri rules for the Schubert bases of $H^*({\rm Gr})$ and $H_*({\rm Gr})$, which expresses the product of a special Schubert class and an arbitrary Schubert class in terms of Schubert classes. A new combinatorial definition for $k$-Schur functions, which represent the Schubert basis of $H_*({\rm Gr})$. A combinatorial interpretation of the pairing $H^*({\rm Gr})\times H_*({\rm Gr}) \rightarrow\mathbb Z$ induced by the cap product.

Classification of Radial Solutions Arising in the Study of Thermal Structures with Thermal Equilibrium or No Flux at the Boundary

Classification of Radial Solutions Arising in the Study of Thermal Structures with Thermal Equilibrium or No Flux at the Boundary
Author: Alfonso Castro
Publisher: American Mathematical Soc.
Total Pages: 87
Release: 2010
Genre: Mathematics
ISBN: 0821847260

The authors provide a complete classification of the radial solutions to a class of reaction diffusion equations arising in the study of thermal structures such as plasmas with thermal equilibrium or no flux at the boundary. In particular, their study includes rapidly growing nonlinearities, that is, those where an exponent exceeds the critical exponent. They describe the corresponding bifurcation diagrams and determine existence and uniqueness of ground states, which play a central role in characterizing those diagrams. They also provide information on the stability-unstability of the radial steady states.

Iwasawa Theory, Projective Modules, and Modular Representations

Iwasawa Theory, Projective Modules, and Modular Representations
Author: Ralph Greenberg
Publisher: American Mathematical Soc.
Total Pages: 198
Release: 2010
Genre: Mathematics
ISBN: 082184931X

This paper shows that properties of projective modules over a group ring $\mathbf{Z}_p[\Delta]$, where $\Delta$ is a finite Galois group, can be used to study the behavior of certain invariants which occur naturally in Iwasawa theory for an elliptic curve $E$. Modular representation theory for the group $\Delta$ plays a crucial role in this study. It is necessary to make a certain assumption about the vanishing of a $\mu$-invariant. The author then studies $\lambda$-invariants $\lambda_E(\sigma)$, where $\sigma$ varies over the absolutely irreducible representations of $\Delta$. He shows that there are non-trivial relationships between these invariants under certain hypotheses.