Species and Hyperplane Arrangements

Species and Hyperplane Arrangements PDF Author: Jose Dario Bastidas Olaya
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
This dissertation has two leading characters : Hopf monoids in the category of species and the Tits algebra of a real hyperplane arrangement. The relation between these two comes from the work of Aguiar and Mahajan (2013), who showed that a (co)commutative Hopf monoid gives rise to a family of (left)right-modules over the Tits algebra of the braid arrangement in all dimensions. One goal of this thesis is to explore the representation theory of the Tits algebra of arbitrary affine arrangements to extend what is known in the case of linear arrangements and to give an insight into some unanswered questions in the field of Hopf monoids. In the first part, we extend the study of characteristic elements of a hyperplane arrangement from the linear to the affine case. We present the basic properties of these elements and apply them to derive numerous results about the characteristic polynomial of an arrangement, from Zaslavsky's formulas to more recent results of Kung and of Klivans and Swartz. We construct several examples of characteristic elements, including one in terms of intrinsic volumes of faces of the arrangement. In the second part, we study deformations $\arr$ of a linear arrangement $\arr_0$ and endow the Tits algebra of $\arr$ with a bimodule structure over the algebra of $\arr_0$. The left module structure sheds some light on the study of exponential sequences of arrangements, in the sense of Stanley. In particular, we construct the Hopf monoid of faces associated with such a sequence and use characteristic elements to deduce formulas for certain bivariate polynomial invariants of these arrangements. In the third part, we endow the polytope subalgebra of deformations of a zonotope with the structure of a module over the Tits algebra of the corresponding hyperplane arrangement. We study algebraic invariants of this module and find relations between statistics on (signed) permutations and the module structure in the case of (type B) generalized permutahedra. In type B, the module structure surprisingly reveals that any family of generators (via signed Minkowski sums) for generalized permutahedra of type B will contain at least

Bimonoids for Hyperplane Arrangements

Bimonoids for Hyperplane Arrangements PDF Author: Marcelo Aguiar
Publisher: Cambridge University Press
ISBN: 110849580X
Category : Mathematics
Languages : en
Pages : 853

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Book Description
The goal of this monograph is to develop Hopf theory in a new setting which features centrally a real hyperplane arrangement. The new theory is parallel to the classical theory of connected Hopf algebras, and relates to it when specialized to the braid arrangement. Joyal's theory of combinatorial species, ideas from Tits' theory of buildings, and Rota's work on incidence algebras inspire and find a common expression in this theory. The authors introduce notions of monoid, comonoid, bimonoid, and Lie monoid relative to a fixed hyperplane arrangement. They also construct universal bimonoids by using generalizations of the classical notions of shuffle and quasishuffle, and establish the Borel-Hopf, Poincar -Birkhoff-Witt, and Cartier-Milnor-Moore theorems in this setting. This monograph opens a vast new area of research. It will be of interest to students and researchers working in the areas of hyperplane arrangements, semigroup theory, Hopf algebras, algebraic Lie theory, operads, and category theory.

Coxeter Bialgebras

Coxeter Bialgebras PDF Author: Marcelo Aguiar
Publisher: Cambridge University Press
ISBN: 100924373X
Category : Mathematics
Languages : en
Pages : 897

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Book Description
The goal of this monograph is to develop Hopf theory in the setting of a real reflection arrangement. The central notion is that of a Coxeter bialgebra which generalizes the classical notion of a connected graded Hopf algebra. The authors also introduce the more structured notion of a Coxeter bimonoid and connect the two notions via a family of functors called Fock functors. These generalize similar functors connecting Hopf monoids in the category of Joyal species and connected graded Hopf algebras. This monograph opens a new chapter in Coxeter theory as well as in Hopf theory, connecting the two. It also relates fruitfully to many other areas of mathematics such as discrete geometry, semigroup theory, associative algebras, algebraic Lie theory, operads, and category theory. It is carefully written, with effective use of tables, diagrams, pictures, and summaries. It will be of interest to students and researchers alike.

Bimonoids for Hyperplane Arrangements

Bimonoids for Hyperplane Arrangements PDF Author: Marcelo Aguiar
Publisher: Cambridge University Press
ISBN: 1108852785
Category : Mathematics
Languages : en
Pages : 854

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Book Description
The goal of this monograph is to develop Hopf theory in a new setting which features centrally a real hyperplane arrangement. The new theory is parallel to the classical theory of connected Hopf algebras, and relates to it when specialized to the braid arrangement. Joyal's theory of combinatorial species, ideas from Tits' theory of buildings, and Rota's work on incidence algebras inspire and find a common expression in this theory. The authors introduce notions of monoid, comonoid, bimonoid, and Lie monoid relative to a fixed hyperplane arrangement. They also construct universal bimonoids by using generalizations of the classical notions of shuffle and quasishuffle, and establish the Borel–Hopf, Poincaré–Birkhoff–Witt, and Cartier–Milnor–Moore theorems in this setting. This monograph opens a vast new area of research. It will be of interest to students and researchers working in the areas of hyperplane arrangements, semigroup theory, Hopf algebras, algebraic Lie theory, operads, and category theory.

Topics in Hyperplane Arrangements

Topics in Hyperplane Arrangements PDF Author: Marcelo Aguiar
Publisher: American Mathematical Soc.
ISBN: 1470437112
Category : Mathematics
Languages : en
Pages : 639

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Book Description
This monograph studies the interplay between various algebraic, geometric and combinatorial aspects of real hyperplane arrangements. It provides a careful, organized and unified treatment of several recent developments in the field, and brings forth many new ideas and results. It has two parts, each divided into eight chapters, and five appendices with background material. Part I gives a detailed discussion on faces, flats, chambers, cones, gallery intervals, lunes and other geometric notions associated with arrangements. The Tits monoid plays a central role. Another important object is the category of lunes which generalizes the classical associative operad. Also discussed are the descent and lune identities, distance functions on chambers, and the combinatorics of the braid arrangement and related examples. Part II studies the structure and representation theory of the Tits algebra of an arrangement. It gives a detailed analysis of idempotents and Peirce decompositions, and connects them to the classical theory of Eulerian idempotents. It introduces the space of Lie elements of an arrangement which generalizes the classical Lie operad. This space is the last nonzero power of the radical of the Tits algebra. It is also the socle of the left ideal of chambers and of the right ideal of Zie elements. Zie elements generalize the classical Lie idempotents. They include Dynkin elements associated to generic half-spaces which generalize the classical Dynkin idempotent. Another important object is the lune-incidence algebra which marks the beginning of noncommutative Möbius theory. These ideas are also brought upon the study of the Solomon descent algebra. The monograph is written with clarity and in sufficient detail to make it accessible to graduate students. It can also serve as a useful reference to experts.

Arrangements, Local Systems and Singularities

Arrangements, Local Systems and Singularities PDF Author: Fouad El Zein
Publisher: Springer Science & Business Media
ISBN: 303460209X
Category : Mathematics
Languages : en
Pages : 325

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Book Description
This volume comprises the Lecture Notes of the CIMPA/TUBITAK Summer School Arrangements, Local systems and Singularities held at Galatasaray University, Istanbul during June 2007. The volume is intended for a large audience in pure mathematics, including researchers and graduate students working in algebraic geometry, singularity theory, topology and related fields. The reader will find a variety of open problems involving arrangements, local systems and singularities proposed by the lecturers at the end of the school.

Hopf Algebras and Tensor Categories

Hopf Algebras and Tensor Categories PDF Author: Nicolás Andruskiewitsch
Publisher: American Mathematical Soc.
ISBN: 0821875647
Category : Mathematics
Languages : en
Pages : 347

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Book Description
This volume contains the proceedings of the Conference on Hopf Algebras and Tensor Categories, held July 4-8, 2011, at the University of Almeria, Almeria, Spain. The articles in this volume cover a wide variety of topics related to the theory of Hopf algebras and its connections to other areas of mathematics. In particular, this volume contains a survey covering aspects of the classification of fusion categories using Morita equivalence methods, a long comprehensive introduction to Hopf algebras in the category of species, and a summary of the status to date of the classification of Hopf algebras of dimensions up to 100. Among other topics discussed in this volume are a study of normalized class sum and generalized character table for semisimple Hopf algebras, a contribution to the classification program of finite dimensional pointed Hopf algebras, relations to the conjecture of De Concini, Kac, and Procesi on representations of quantum groups at roots of unity, a categorical approach to the Drinfeld double of a braided Hopf algebra via Hopf monads, an overview of Hom-Hopf algebras, and several discussions on the crossed product construction in different settings.

Spectrum of Hyperplane Arrangements in Four Variables

Spectrum of Hyperplane Arrangements in Four Variables PDF Author: Youngho Yoon
Publisher:
ISBN:
Category :
Languages : en
Pages : 48

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Book Description


Cell Complexes, Poset Topology and the Representation Theory of Algebras Arising in Algebraic Combinatorics and Discrete Geometry

Cell Complexes, Poset Topology and the Representation Theory of Algebras Arising in Algebraic Combinatorics and Discrete Geometry PDF Author: Stuart Margolis
Publisher: American Mathematical Society
ISBN: 1470450429
Category : Mathematics
Languages : en
Pages : 135

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Book Description
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Classical Hopf Algebras and Their Applications

Classical Hopf Algebras and Their Applications PDF Author: Pierre Cartier
Publisher: Springer Nature
ISBN: 3030778452
Category : Mathematics
Languages : en
Pages : 277

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Book Description
This book is dedicated to the structure and combinatorics of classical Hopf algebras. Its main focus is on commutative and cocommutative Hopf algebras, such as algebras of representative functions on groups and enveloping algebras of Lie algebras, as explored in the works of Borel, Cartier, Hopf and others in the 1940s and 50s. The modern and systematic treatment uses the approach of natural operations, illuminating the structure of Hopf algebras by means of their endomorphisms and their combinatorics. Emphasizing notions such as pseudo-coproducts, characteristic endomorphisms, descent algebras and Lie idempotents, the text also covers the important case of enveloping algebras of pre-Lie algebras. A wide range of applications are surveyed, highlighting the main ideas and fundamental results. Suitable as a textbook for masters or doctoral level programs, this book will be of interest to algebraists and anyone working in one of the fields of application of Hopf algebras.