On Unimodality of Hilbert Functions of Artinian Level Algebras of Codimension 3 and Type 2 and 3

On Unimodality of Hilbert Functions of Artinian Level Algebras of Codimension 3 and Type 2 and 3 PDF Author: Valeria D'Orazio
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages :

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Book Description
We prove the unimodality of the Hilbert Function for some classes of codimension three graded algebras of Cohen-Macaulay types 2 and 3. The method of proof uses the explicit structure theorems similar to the structure theorems for Gorenstein algebras in codimension 3. Using the structure of the resolution, we write the Hilbert function explicitly and thus calculate the h-vector and verify it is indeed unimodal.

The Hilbert Function of a Level Algebra

The Hilbert Function of a Level Algebra PDF Author: A. V. Geramita
Publisher: American Mathematical Soc.
ISBN: 0821839403
Category : Mathematics
Languages : en
Pages : 154

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Book Description
Let $R$ be a polynomial ring over an algebraically closed field and let $A$ be a standard graded Cohen-Macaulay quotient of $R$. The authors state that $A$ is a level algebra if the last module in the minimal free resolution of $A$ (as $R$-module) is of the form $R(-s)a$, where $s$ and $a$ are positive integers. When $a=1$ these are also known as Gorenstein algebras. The basic question addressed in this paper is: What can be the Hilbert Function of a level algebra? The authors consider the question in several particular cases, e.g., when $A$ is an Artinian algebra, or when $A$ is the homogeneous coordinate ring of a reduced set of points, or when $A$ satisfies the Weak Lefschetz Property. The authors give new methods for showing that certain functions are NOT possible as the Hilbert function of a level algebra and also give new methods to construct level algebras. In a (rather long) appendix, the authors apply their results to give complete lists of all possible Hilbert functions in the case that the codimension of $A = 3$, $s$ is small and $a$ takes on certain fixed values.

On the Shape of a Pure $O$-Sequence

On the Shape of a Pure $O$-Sequence PDF Author: Mats Boij
Publisher: American Mathematical Soc.
ISBN: 0821869108
Category : Mathematics
Languages : en
Pages : 93

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Book Description
A monomial order ideal is a finite collection X of (monic) monomials such that, whenever M∈X and N divides M, then N∈X. Hence X is a poset, where the partial order is given by divisibility. If all, say t t, maximal monomials of X have the same degree, then X is pure (of type t). A pure O-sequence is the vector, h_=(h0=1,h1,...,he), counting the monomials of X in each degree. Equivalently, pure O-sequences can be characterized as the f-vectors of pure multicomplexes, or, in the language of commutative algebra, as the h h-vectors of monomial Artinian level algebras. Pure O-sequences had their origin in one of the early works of Stanley's in this area, and have since played a significant role in at least three different disciplines: the study of simplicial complexes and their f f-vectors, the theory of level algebras, and the theory of matroids. This monograph is intended to be the first systematic study of the theory of pure O-sequences.

Commutative Algebra

Commutative Algebra PDF Author: Irena Peeva
Publisher: Springer Science & Business Media
ISBN: 1461452929
Category : Mathematics
Languages : en
Pages : 705

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Book Description
This contributed volume brings together the highest quality expository papers written by leaders and talented junior mathematicians in the field of Commutative Algebra. Contributions cover a very wide range of topics, including core areas in Commutative Algebra and also relations to Algebraic Geometry, Algebraic Combinatorics, Hyperplane Arrangements, Homological Algebra, and String Theory. The book aims to showcase the area, especially for the benefit of junior mathematicians and researchers who are new to the field; it will aid them in broadening their background and to gain a deeper understanding of the current research in this area. Exciting developments are surveyed and many open problems are discussed with the aspiration to inspire the readers and foster further research.

Mathematical Reviews

Mathematical Reviews PDF Author:
Publisher:
ISBN:
Category : Mathematics
Languages : en
Pages : 1208

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Rendiconti del Seminario matematico

Rendiconti del Seminario matematico PDF Author: Seminario matematico (Turin, Italy)
Publisher:
ISBN:
Category : Mathematics
Languages : en
Pages : 434

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Book Description


Queen's Papers in Pure and Applied Mathematics

Queen's Papers in Pure and Applied Mathematics PDF Author: Queen's University (Kingston, Ont.)
Publisher:
ISBN:
Category : Mathematics
Languages : en
Pages : 300

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The Lefschetz Properties

The Lefschetz Properties PDF Author: Tadahito Harima
Publisher: Springer
ISBN: 3642382061
Category : Mathematics
Languages : en
Pages : 268

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Book Description
This is a monograph which collects basic techniques, major results and interesting applications of Lefschetz properties of Artinian algebras. The origin of the Lefschetz properties of Artinian algebras is the Hard Lefschetz Theorem, which is a major result in algebraic geometry. However, for the last two decades, numerous applications of the Lefschetz properties to other areas of mathematics have been found, as a result of which the theory of the Lefschetz properties is now of great interest in its own right. It also has ties to other areas, including combinatorics, algebraic geometry, algebraic topology, commutative algebra and representation theory. The connections between the Lefschetz property and other areas of mathematics are not only diverse, but sometimes quite surprising, e.g. its ties to the Schur-Weyl duality. This is the first book solely devoted to the Lefschetz properties and is the first attempt to treat those properties systematically.

Generalized Principal Component Analysis

Generalized Principal Component Analysis PDF Author: René Vidal
Publisher: Springer
ISBN: 0387878114
Category : Science
Languages : en
Pages : 590

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Book Description
This book provides a comprehensive introduction to the latest advances in the mathematical theory and computational tools for modeling high-dimensional data drawn from one or multiple low-dimensional subspaces (or manifolds) and potentially corrupted by noise, gross errors, or outliers. This challenging task requires the development of new algebraic, geometric, statistical, and computational methods for efficient and robust estimation and segmentation of one or multiple subspaces. The book also presents interesting real-world applications of these new methods in image processing, image and video segmentation, face recognition and clustering, and hybrid system identification etc. This book is intended to serve as a textbook for graduate students and beginning researchers in data science, machine learning, computer vision, image and signal processing, and systems theory. It contains ample illustrations, examples, and exercises and is made largely self-contained with three Appendices which survey basic concepts and principles from statistics, optimization, and algebraic-geometry used in this book. René Vidal is a Professor of Biomedical Engineering and Director of the Vision Dynamics and Learning Lab at The Johns Hopkins University. Yi Ma is Executive Dean and Professor at the School of Information Science and Technology at ShanghaiTech University. S. Shankar Sastry is Dean of the College of Engineering, Professor of Electrical Engineering and Computer Science and Professor of Bioengineering at the University of California, Berkeley.

Intersection Homology & Perverse Sheaves

Intersection Homology & Perverse Sheaves PDF Author: Laurenţiu G. Maxim
Publisher: Springer Nature
ISBN: 3030276449
Category : Mathematics
Languages : en
Pages : 270

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Book Description
This textbook provides a gentle introduction to intersection homology and perverse sheaves, where concrete examples and geometric applications motivate concepts throughout. By giving a taste of the main ideas in the field, the author welcomes new readers to this exciting area at the crossroads of topology, algebraic geometry, analysis, and differential equations. Those looking to delve further into the abstract theory will find ample references to facilitate navigation of both classic and recent literature. Beginning with an introduction to intersection homology from a geometric and topological viewpoint, the text goes on to develop the sheaf-theoretical perspective. Then algebraic geometry comes to the fore: a brief discussion of constructibility opens onto an in-depth exploration of perverse sheaves. Highlights from the following chapters include a detailed account of the proof of the Beilinson–Bernstein–Deligne–Gabber (BBDG) decomposition theorem, applications of perverse sheaves to hypersurface singularities, and a discussion of Hodge-theoretic aspects of intersection homology via Saito’s deep theory of mixed Hodge modules. An epilogue offers a succinct summary of the literature surrounding some recent applications. Intersection Homology & Perverse Sheaves is suitable for graduate students with a basic background in topology and algebraic geometry. By building context and familiarity with examples, the text offers an ideal starting point for those entering the field. This classroom-tested approach opens the door to further study and to current research.