Diagram Cohomology and Isovariant Homotopy Theory
Diagram Cohomology and Isovariant Homotopy Theory

Author: Giora Dula

Publisher: American Mathematical Soc.

Published: 1994

Total Pages: 97

ISBN-13: 0821825895

DOWNLOAD EBOOK

Obstruction theoretic methods are introduced into isovariant homotopy theory for a class of spaces with group actions; the latter includes all smooth actions of cyclic groups of prime power order. The central technical result is an equivalence between isovariant homotopy and specific equivariant homotopy theories for diagrams under suitable conditions. This leads to isovariant Whitehead theorems, an obstruction-theoretic approach to isovariant homotopy theory with obstructions in cohomology groups of ordinary and equivalent diagrams, and qualitative computations for rational homotopy groups of certain spaces of isovariant self maps of linear spheres. The computations show that these homotopy groups are often far more complicated than the rational homotopy groups for the corresponding spaces of equivariant self maps. Subsequent work will use these computations to construct new families of smooth actions on spheres that are topologically linear but differentiably nonlinear.

On Finite Groups and Homotopy Theory
On Finite Groups and Homotopy Theory

Author: Ran Levi

Publisher: American Mathematical Soc.

Published: 1995

Total Pages: 121

ISBN-13: 0821804014

DOWNLOAD EBOOK

In part 1 we study the homology, homotopy, and stable homotopy of [capital Greek]Omega[italic capital]B[lowercase Greek]Pi[up arrowhead][over][subscript italic]p, where [italic capital]G is a finite [italic]p-perfect group. In part 2 we define the concept of resolutions by fibrations over an arbitrary family of spaces.

Generalized Tate Cohomology
Generalized Tate Cohomology

Author: John Patrick Campbell Greenlees

Publisher: American Mathematical Soc.

Published: 1995

Total Pages: 193

ISBN-13: 0821826034

DOWNLOAD EBOOK

Let [italic capital]G be a compact Lie group, [italic capitals]EG a contractible free [italic capital]G-space and let [italic capitals]E~G be the unreduced suspension of [italic capitals]EG with one of the cone points as basepoint. Let [italic]k*[over][subscript italic capital]G be a [italic capital]G-spectrum. Let [italic capital]X+ denote the disjoint union of [italic capital]X and a [italic capital]G-fixed basepoint. Define the [italic capital]G-spectra [italic]f([italic]k*[over][subscript italic capital]G) = [italic]k*[over][subscript italic capital]G [up arrowhead symbol] [italic capitals]EG+, [italic]c([italic]k*[over][subscript italic capital]G) = [italic capital]F([italic capitals]EG+,[italic]k*[over][subscript italic capital]G), and [italic]t([italic]k[subscript italic capital]G)* = [italic capital]F([italic capitals]EG+,[italic]k*[over][subscript italic capital]G) [up arrowhead symbol] [italic capitals]E~G. The last of these is the [italic capital]G-spectrum representing the generalized Tate homology and cohomology theories associated to [italic]k[subscript italic capital]G. Here [italic capital]F([italic capitals]EG+,[italic]k*[over][subscript italic capital]G) is the function space spectrum. The authors develop the properties of these theories, illustrating the manner in which they generalize the classical Tate-Swan theories.

Filtrations on the Homology of Algebraic Varieties
Filtrations on the Homology of Algebraic Varieties

Author: Eric M. Friedlander

Publisher: American Mathematical Soc.

Published: 1994

Total Pages: 126

ISBN-13: 0821825917

DOWNLOAD EBOOK

This work provides a detailed exposition of a classical topic from a very recent viewpoint. Friedlander and Mazur describe some foundational aspects of ``Lawson homology'' for complex projective algebraic varieties, a homology theory defined in terms of homotopy groups of spaces of algebraic cycles. Attention is paid to methods of group completing abelian topological monoids. The authors study properties of Chow varieties, especially in connection with algebraic correspondences relating algebraic varieties. Operations on Lawson homology are introduced and analysed. These operations lead to a filtration on the singular homology of algebraic varieties, which is identified in terms of correspondences and related to classical filtrations of Hodge and Grothendieck.

Orthogonal Decompositions and Functional Limit Theorems for Random Graph Statistics
Orthogonal Decompositions and Functional Limit Theorems for Random Graph Statistics

Author: Svante Janson

Publisher: American Mathematical Soc.

Published: 1994

Total Pages: 90

ISBN-13: 082182595X

DOWNLOAD EBOOK

We define an orthogonal basis in the space of real-valued functions of a random graph, and prove a functional limit theorem for this basis. Limit theorems for other functions then follow by decomposition. The results include limit theorems for the two random graph models [italic]G[subscript italic]n, [subscript italic]p and [italic]G[subscript italic]n, [subscript italic]m as well as functional limit theorems for the evolution of a random graph and results on the maximum of a function during the evolution. Both normal and non-normal limits are obtained. As examples, applications are given to subgraph counts and to vertex degrees.

Some Special Properties of the Adjunction Theory for $3$-Folds in $\mathbb P^5$
Some Special Properties of the Adjunction Theory for $3$-Folds in $\mathbb P^5$

Author: Mauro Beltrametti

Publisher: American Mathematical Soc.

Published: 1995

Total Pages: 79

ISBN-13: 0821802348

DOWNLOAD EBOOK

This work studies the adjunction theory of smooth 3-folds in P]5. Because of the many special restrictions on such 3-folds, the structure of the adjunction theoretic reductions are especially simple, e.g. the 3-fold equals its first reduction, the second reduction is smooth except possibly for a few explicit low degrees, and the formulae relating the projective invariants of the given 3-fold with the invariants of its second reduction are very explicit. Tables summarizing the classification of such 3-folds up to degree 12 are included. Many of the general results are shown to hold for smooth projective n-folds embedded in P]N with N 2n -1.

Lebesgue Theory in the Bidual of C(X)
Lebesgue Theory in the Bidual of C(X)

Author: Samuel Kaplan

Publisher: American Mathematical Soc.

Published: 1996

Total Pages: 143

ISBN-13: 0821804634

DOWNLOAD EBOOK

The present work is based upon our monograph "The Bidual of [italic capital]C([italic capital]X)" ([italic capital]X being compact). We generalize to the bidual the theory of Lebesgue integration, with respect to Radon measures on [italic capital]X, of bounded functions. The bidual of [italic capital]C([italic capital]X) contains this space of bounded functions, but is much more 'spacious', so the body of results can be expected to be richer. Finally, we show that by projection onto the space of bounded functions, the standard theory is obtained.

The Topological Classification of Stratified Spaces
The Topological Classification of Stratified Spaces

Author: Shmuel Weinberger

Publisher: University of Chicago Press

Published: 1994

Total Pages: 314

ISBN-13: 9780226885667

DOWNLOAD EBOOK

This book provides the theory for stratified spaces, along with important examples and applications, that is analogous to the surgery theory for manifolds. In the first expository account of this field, Weinberger provides topologists with a new way of looking at the classification theory of singular spaces with his original results. Divided into three parts, the book begins with an overview of modern high-dimensional manifold theory. Rather than including complete proofs of all theorems, Weinberger demonstrates key constructions, gives convenient formulations, and shows the usefulness of the technology. Part II offers the parallel theory for stratified spaces. Here, the topological category is most completely developed using the methods of "controlled topology." Many examples illustrating the topological invariance and noninvariance of obstructions and characteristic classes are provided. Applications for embeddings and immersions of manifolds, for the geometry of group actions, for algebraic varieties, and for rigidity theorems are found in Part III. This volume will be of interest to topologists, as well as mathematicians in other fields such as differential geometry, operator theory, and algebraic geometry.

Littlewood-Paley Theory on Spaces of Homogeneous Type and the Classical Function Spaces
Littlewood-Paley Theory on Spaces of Homogeneous Type and the Classical Function Spaces

Author: Yongsheng Han

Publisher: American Mathematical Soc.

Published: 1994

Total Pages: 138

ISBN-13: 0821825925

DOWNLOAD EBOOK

In this work, Han and Sawyer extend Littlewood-Paley theory, Besov spaces, and Triebel-Lizorkin spaces to the general setting of a space of homogeneous type. For this purpose, they establish a suitable analogue of the Calder 'on reproducing formula and use it to extend classical results on atomic decomposition, interpolation, and T1 and Tb theorems. Some new results in the classical setting are also obtained: atomic decompositions with vanishing b-moment, and Littlewood-Paley characterizations of Besov and Triebel-Lizorkin spaces with only half the usual smoothness and cancellation conditions on the approximate identity.

Finite Rational Matrix Groups
Finite Rational Matrix Groups

Author: Gabriele Nebe

Publisher: American Mathematical Soc.

Published: 1995

Total Pages: 158

ISBN-13: 0821803433

DOWNLOAD EBOOK

The study of finite rational matrix groups reduces to the investigation of the maximal finite irreducible matrix groups and their natural lattices, which often turn out to have rather beautiful geometric and arithmetic properties. This book presents a full classification in dimensions up to 23 and with restrictions in dimensions and p +1 and p-1 for all prime numbers p. Nonmaximal finite groups might act on several types of lattices and therefore embed into more than one maximal finite group. This gives rise to a simplicial complex interrelating the maximal finite groups and measuring the complexity of the dimension. Group theory, integral representation theory, arithmetic theory of quadratic forms and algorithmic methods are used.