Download or read book Property T for Groups Graded by Root Systems written by Mikhail Ershov and published by . This book was released on 2017 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors introduce and study the class of groups graded by root systems. They prove that if \Phi is an irreducible classical root system of rank \geq 2 and G is a group graded by \Phi, then under certain natural conditions on the grading, the union of the root subgroups is a Kazhdan subset of G. As the main application of this theorem the authors prove that for any reduced irreducible classical root system \Phi of rank \geq 2 and a finitely generated commutative ring R with 1, the Steinberg group {\mathrm St}_{\Phi}(R) and the elementary Chevalley group \mathbb E_{\Phi}(R) have property (T).

Download or read book Property T for Groups Graded by Root Systems written by Mikhail Ershov and published by American Mathematical Soc.. This book was released on 2017-09-25 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors introduce and study the class of groups graded by root systems. They prove that if is an irreducible classical root system of rank and is a group graded by , then under certain natural conditions on the grading, the union of the root subgroups is a Kazhdan subset of . As the main application of this theorem the authors prove that for any reduced irreducible classical root system of rank and a finitely generated commutative ring with , the Steinberg group and the elementary Chevalley group have property . They also show that there exists a group with property which maps onto all finite simple groups of Lie type and rank , thereby providing a “unified” proof of expansion in these groups.

Download or read book Tensor Products and Regularity Properties of Cuntz Semigroups written by Ramon Antoine and published by American Mathematical Soc.. This book was released on 2018-02-23 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Cuntz semigroup of a -algebra is an important invariant in the structure and classification theory of -algebras. It captures more information than -theory but is often more delicate to handle. The authors systematically study the lattice and category theoretic aspects of Cuntz semigroups. Given a -algebra , its (concrete) Cuntz semigroup is an object in the category of (abstract) Cuntz semigroups, as introduced by Coward, Elliott and Ivanescu. To clarify the distinction between concrete and abstract Cuntz semigroups, the authors call the latter -semigroups. The authors establish the existence of tensor products in the category and study the basic properties of this construction. They show that is a symmetric, monoidal category and relate with for certain classes of -algebras. As a main tool for their approach the authors introduce the category of pre-completed Cuntz semigroups. They show that is a full, reflective subcategory of . One can then easily deduce properties of from respective properties of , for example the existence of tensor products and inductive limits. The advantage is that constructions in are much easier since the objects are purely algebraic.

Download or read book Maximal Abelian Sets of Roots written by R. Lawther and published by American Mathematical Soc.. This book was released on 2018-01-16 with total page 219 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work the author lets be an irreducible root system, with Coxeter group . He considers subsets of which are abelian, meaning that no two roots in the set have sum in . He classifies all maximal abelian sets (i.e., abelian sets properly contained in no other) up to the action of : for each -orbit of maximal abelian sets we provide an explicit representative , identify the (setwise) stabilizer of in , and decompose into -orbits. Abelian sets of roots are closely related to abelian unipotent subgroups of simple algebraic groups, and thus to abelian -subgroups of finite groups of Lie type over fields of characteristic . Parts of the work presented here have been used to confirm the -rank of , and (somewhat unexpectedly) to obtain for the first time the -ranks of the Monster and Baby Monster sporadic groups, together with the double cover of the latter. Root systems of classical type are dealt with quickly here; the vast majority of the present work concerns those of exceptional type. In these root systems the author introduces the notion of a radical set; such a set corresponds to a subgroup of a simple algebraic group lying in the unipotent radical of a certain maximal parabolic subgroup. The classification of radical maximal abelian sets for the larger root systems of exceptional type presents an interesting challenge; it is accomplished by converting the problem to that of classifying certain graphs modulo a particular equivalence relation.

Download or read book On Non Generic Finite Subgroups of Exceptional Algebraic Groups written by Alastair J. Litterick and published by American Mathematical Soc.. This book was released on 2018-05-29 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book From Vertex Operator Algebras to Conformal Nets and Back written by Sebastiano Carpi and published by American Mathematical Soc.. This book was released on 2018-08-09 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors consider unitary simple vertex operator algebras whose vertex operators satisfy certain energy bounds and a strong form of locality and call them strongly local. They present a general procedure which associates to every strongly local vertex operator algebra V a conformal net AV acting on the Hilbert space completion of V and prove that the isomorphism class of AV does not depend on the choice of the scalar product on V. They show that the class of strongly local vertex operator algebras is closed under taking tensor products and unitary subalgebras and that, for every strongly local vertex operator algebra V, the map W↦AW gives a one-to-one correspondence between the unitary subalgebras W of V and the covariant subnets of AV.

Download or read book A Morse Bott Approach to Monopole Floer Homology and the Triangulation Conjecture written by Francesco Lin and published by American Mathematical Soc.. This book was released on 2018-10-03 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the present work the author generalizes the construction of monopole Floer homology due to Kronheimer and Mrowka to the case of a gradient flow with Morse-Bott singularities. Focusing then on the special case of a three-manifold equipped equipped with a structure which is isomorphic to its conjugate, the author defines the counterpart in this context of Manolescu's recent Pin(2)-equivariant Seiberg-Witten-Floer homology. In particular, the author provides an alternative approach to his disproof of the celebrated Triangulation conjecture.

Download or read book Algebraic Q Groups as Abstract Groups written by Olivier Frécon and published by American Mathematical Soc.. This book was released on 2018-10-03 with total page 99 pages. Available in PDF, EPUB and Kindle. Book excerpt: The author analyzes the abstract structure of algebraic groups over an algebraically closed field . For of characteristic zero and a given connected affine algebraic Q -group, the main theorem describes all the affine algebraic Q -groups such that the groups and are isomorphic as abstract groups. In the same time, it is shown that for any two connected algebraic Q -groups and , the elementary equivalence of the pure groups and implies that they are abstractly isomorphic. In the final section, the author applies his results to characterize the connected algebraic groups, all of whose abstract automorphisms are standard, when is either Q or of positive characteristic. In characteristic zero, a fairly general criterion is exhibited.

Download or read book Systems of Transversal Sections Near Critical Energy Levels of Hamiltonian Systems in R written by Naiara V. de Paulo and published by American Mathematical Soc.. This book was released on 2018-03-19 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this article the authors study Hamiltonian flows associated to smooth functions R R restricted to energy levels close to critical levels. They assume the existence of a saddle-center equilibrium point in the zero energy level . The Hamiltonian function near is assumed to satisfy Moser's normal form and is assumed to lie in a strictly convex singular subset of . Then for all small, the energy level contains a subset near , diffeomorphic to the closed -ball, which admits a system of transversal sections , called a foliation. is a singular foliation of and contains two periodic orbits and as binding orbits. is the Lyapunoff orbit lying in the center manifold of , has Conley-Zehnder index and spans two rigid planes in . has Conley-Zehnder index and spans a one parameter family of planes in . A rigid cylinder connecting to completes . All regular leaves are transverse to the Hamiltonian vector field. The existence of a homoclinic orbit to in follows from this foliation.

Download or read book Steinberg Groups for Jordan Pairs written by Ottmar Loos and published by Springer Nature. This book was released on 2020-01-10 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present monograph develops a unified theory of Steinberg groups, independent of matrix representations, based on the theory of Jordan pairs and the theory of 3-graded locally finite root systems. The development of this approach occurs over six chapters, progressing from groups with commutator relations and their Steinberg groups, then on to Jordan pairs, 3-graded locally finite root systems, and groups associated with Jordan pairs graded by root systems, before exploring the volume's main focus: the definition of the Steinberg group of a root graded Jordan pair by a small set of relations, and its central closedness. Several original concepts, such as the notions of Jordan graphs and Weyl elements, provide readers with the necessary tools from combinatorics and group theory. Steinberg Groups for Jordan Pairs is ideal for PhD students and researchers in the fields of elementary groups, Steinberg groups, Jordan algebras, and Jordan pairs. By adopting a unified approach, anybody interested in this area who seeks an alternative to case-by-case arguments and explicit matrix calculations will find this book essential.

Download or read book Szeg Kernel Asymptotics for High Power of CR Line Bundles and Kodaira Embedding Theorems on CR Manifolds written by Chin-Yu Hsiao and published by American Mathematical Soc.. This book was released on 2018-08-09 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Let X be an abstract not necessarily compact orientable CR manifold of dimension 2n−1, n⩾2, and let Lk be the k-th tensor power of a CR complex line bundle L over X. Given q∈{0,1,…,n−1}, let □(q)b,k be the Gaffney extension of Kohn Laplacian for (0,q) forms with values in Lk. For λ≥0, let Π(q)k,≤λ:=E((−∞,λ]), where E denotes the spectral measure of □(q)b,k. In this work, the author proves that Π(q)k,≤k−N0F∗k, FkΠ(q)k,≤k−N0F∗k, N0≥1, admit asymptotic expansions with respect to k on the non-degenerate part of the characteristic manifold of □(q)b,k, where Fk is some kind of microlocal cut-off function. Moreover, we show that FkΠ(q)k,≤0F∗k admits a full asymptotic expansion with respect to k if □(q)b,k has small spectral gap property with respect to Fk and Π(q)k,≤0 is k-negligible away the diagonal with respect to Fk. By using these asymptotics, the authors establish almost Kodaira embedding theorems on CR manifolds and Kodaira embedding theorems on CR manifolds with transversal CR S1 action.

Download or read book Holomorphic Automorphic Forms and Cohomology written by Roelof Bruggeman and published by American Mathematical Soc.. This book was released on 2018-05-29 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Elliptic PDEs on Compact Ricci Limit Spaces and Applications written by Shouhei Honda and published by American Mathematical Soc.. This book was released on 2018-05-29 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this paper the author studies elliptic PDEs on compact Gromov-Hausdorff limit spaces of Riemannian manifolds with lower Ricci curvature bounds. In particular the author establishes continuities of geometric quantities, which include solutions of Poisson's equations, eigenvalues of Schrödinger operators, generalized Yamabe constants and eigenvalues of the Hodge Laplacian, with respect to the Gromov-Hausdorff topology. The author applies these to the study of second-order differential calculus on such limit spaces.

Download or read book Mathematical Study of Degenerate Boundary Layers A Large Scale Ocean Circulation Problem written by Anne-Laure Dalibard and published by American Mathematical Soc.. This book was released on 2018-05-29 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Globally Generated Vector Bundles with Small C1 on Projective Spaces written by Cristian Anghel and published by American Mathematical Soc.. This book was released on 2018-05-29 with total page 107 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Neckpinch Dynamics for Asymmetric Surfaces Evolving by Mean Curvature Flow written by Zhou Gang and published by American Mathematical Soc.. This book was released on 2018-05-29 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Degree Spectra of Relations on a Cone written by Matthew Harrison-Trainor and published by American Mathematical Soc.. This book was released on 2018-05-29 with total page 107 pages. Available in PDF, EPUB and Kindle. Book excerpt: