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Dominance Order
In discrete mathematics, dominance order (synonyms: dominance ordering, majorization order, natural ordering) is a partial order on the set of partition (number theory), partitions of a positive integer ''n'' that plays an important role in algebraic combinatorics and representation theory, especially in the context of symmetric functions and representation theory of the symmetric group. Definition If ''p'' = (''p''1,''p''2,…) and ''q'' = (''q''1,''q''2,…) are partitions of ''n'', with the parts arranged in the weakly decreasing order, then ''p'' precedes ''q'' in the dominance order if for any ''k'' ≥ 1, the sum of the ''k'' largest parts of ''p'' is less than or equal to the sum of the ''k'' largest parts of ''q'': : p\trianglelefteq q \text p_1+\cdots+p_k \leq q_1+\cdots+q_k \text k\geq 1. In this definition, partitions are extended by appending zero parts at the end as necessary. Properties of the dominance ordering * Among the partitions of ''n'', (1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dominance Order Partitions Of 6
Dominance may refer to: Social relationships * Dominance hierarchy or social hierarchy, an organizational form by which individuals within a community control the distribution of resources within the community * Expressions of dominance in human relationships in general * Dominance and submission, set of behaviors, customs, and rituals in an erotic or lifestyle context * Social dominance theory, a theory of intergroup relations * Social dominance orientation, a personality trait * Abusive power and control, the way that an abusive person gains and maintains power and control over another person *Dual strategies theory, dominance and its counterpart prestige as two strategies for gaining status in human hierarchies Science * Dominance (psychology), assesses a person's characteristic feelings of control and influence over his life circumstances versus feelings of being controlled and influenced by others or events Biology * Dominance (ethology), in animal behaviour and anthropology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antihomomorphism
In mathematics, an antihomomorphism is a type of function defined on sets with multiplication that reverses the order of multiplication. An antiautomorphism is a bijective antihomomorphism, i.e. an antiisomorphism, from a set to itself. From bijectivity it follows that antiautomorphisms have inverses, and that the inverse of an antiautomorphism is also an antiautomorphism. Definition Informally, an antihomomorphism is a map that switches the order of multiplication. Formally, an antihomomorphism between structures X and Y is a homomorphism \phi\colon X \to Y^, where Y^ equals Y as a set, but has its multiplication reversed to that defined on Y. Denoting the (generally non-commutative) multiplication on Y by \cdot, the multiplication on Y^, denoted by *, is defined by x*y := y \cdot x. The object Y^ is called the opposite object to Y (respectively, opposite group, opposite algebra, opposite category etc.). This definition is equivalent to that of a homomorphism \phi\colon X^ \t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algebraic Combinatorics
Algebraic combinatorics is an area of mathematics that employs methods of abstract algebra, notably group theory and representation theory, in various combinatorial contexts and, conversely, applies combinatorial techniques to problems in algebra. History The term "algebraic combinatorics" was introduced in the late 1970s. Through the early or mid-1990s, typical combinatorial objects of interest in algebraic combinatorics either admitted a lot of symmetries (association schemes, strongly regular graphs, posets with a group action) or possessed a rich algebraic structure, frequently of representation theoretic origin (symmetric functions, Young tableaux). This period is reflected in the area 05E, ''Algebraic combinatorics'', of the AMS Mathematics Subject Classification, introduced in 1991. Scope Algebraic combinatorics has come to be seen more expansively as an area of mathematics where the interaction of combinatorial and algebraic methods is particularly strong and significa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enumerative Combinatorics
Enumerative combinatorics is an area of combinatorics that deals with the number of ways that certain patterns can be formed. Two examples of this type of problem are counting combinations and counting permutations. More generally, given an infinite collection of finite sets ''S''''i'' indexed by the natural numbers, enumerative combinatorics seeks to describe a ''counting function'' which counts the number of objects in ''S''''n'' for each ''n''. Although counting the number of elements in a set is a rather broad mathematical problem, many of the problems that arise in applications have a relatively simple combinatorial description. The twelvefold way provides a unified framework for counting permutations, combinations and partitions. The simplest such functions are ''closed formulas'', which can be expressed as a composition of elementary functions such as factorials, powers, and so on. For instance, as shown below, the number of different possible orderings of a deck of '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Majorization
In mathematics, majorization is a preorder on vectors of real numbers. Let ^_,\ i=1,\,\ldots,\,n denote the i-th largest element of the vector \mathbf\in\mathbb^n. Given \mathbf,\ \mathbf \in \mathbb^n, we say that \mathbf weakly majorizes (or dominates) \mathbf from below (or equivalently, we say that \mathbf is weakly majorized (or dominated) by \mathbf from below) denoted as \mathbf \succ_w \mathbf if \sum_^k x_^ \geq \sum_^k y_^ for all k=1,\,\dots,\,d. If in addition \sum_^d x_i^ = \sum_^d y_i^, we say that \mathbf majorizes (or dominates) \mathbf , written as \mathbf \succ \mathbf , or equivalently, we say that \mathbf is majorized (or dominated) by \mathbf. The order of the entries of the vectors \mathbf or \mathbf does not affect the majorization, e.g., the statement (1,2)\prec (0,3) is simply equivalent to (2,1)\prec (3,0). As a consequence, majorization is not a partial order, since \mathbf \succ \mathbf and \mathbf \succ \mathbf do not imply \mathbf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Young's Lattice
In mathematics, Young's lattice is a lattice that is formed by all integer partitions. It is named after Alfred Young, who, in a series of papers ''On quantitative substitutional analysis,'' developed the representation theory of the symmetric group. In Young's theory, the objects now called Young diagrams and the partial order on them played a key, even decisive, role. Young's lattice prominently figures in algebraic combinatorics, forming the simplest example of a differential poset in the sense of . It is also closely connected with the crystal bases for affine Lie algebras. Definition Young's lattice is a lattice (and hence also a partially ordered set) ''Y'' formed by all integer partitions ordered by inclusion of their Young diagrams (or Ferrers diagrams). Significance The traditional application of Young's lattice is to the description of the irreducible representations of symmetric groups S''n'' for all ''n'', together with their branching properties, in characteris ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Young Tableaux
In mathematics, a Young tableau (; plural: tableaux) is a combinatorial object useful in representation theory and Schubert calculus. It provides a convenient way to describe the group representations of the symmetric and general linear groups and to study their properties. Young tableaux were introduced by Alfred Young, a mathematician at Cambridge University, in 1900. They were then applied to the study of the symmetric group by Georg Frobenius in 1903. Their theory was further developed by many mathematicians, including Percy MacMahon, W. V. D. Hodge, G. de B. Robinson, Gian-Carlo Rota, Alain Lascoux, Marcel-Paul Schützenberger and Richard P. Stanley. Definitions ''Note: this article uses the English convention for displaying Young diagrams and tableaux''. Diagrams A Young diagram (also called a Ferrers diagram, particularly when represented using dots) is a finite collection of boxes, or cells, arranged in left-justified rows, with the row lengths in non-increasing o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tableaux Dominance
The International Conference on Automated Reasoning with Analytic Tableaux and Related Methods (TABLEAUX) is an annual international academic conference that deals with all aspects of automated reasoning with analytic tableaux. Periodically, it joins with CADE and TPHOLs into the International Joint Conference on Automated Reasoning (IJCAR). The first table convened in 1992. Since 1995, the proceedings of this conference have been published by Springer's LNAI series. In August 2006 TABLEAUX was part of the Federated Logic Conference in Seattle, USA. The following TABLEAUX were held in 2007 in Aix en Provence, France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ..., as part of IJCAR 2008, in Sydney, Australia, as TABLEAUX 2009, in Oslo, Norway, as part of IJCAR 2010, Edinburgh, UK ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Möbius Function (combinatorics)
In order theory, a field of mathematics, an incidence algebra is an associative algebra, defined for every locally finite partially ordered set and commutative ring with unity. Subalgebras called reduced incidence algebras give a natural construction of various types of generating functions used in combinatorics and number theory. Definition A locally finite poset is one in which every closed interval : 'a, b''= is finite. The members of the incidence algebra are the functions ''f'' assigning to each nonempty interval 'a, b''a scalar ''f''(''a'', ''b''), which is taken from the ''ring of scalars'', a commutative ring with unity. On this underlying set one defines addition and scalar multiplication pointwise, and "multiplication" in the incidence algebra is a convolution defined by :(f*g)(a, b)=\sum_f(a, x)g(x, b). An incidence algebra is finite-dimensional if and only if the underlying poset is finite. Related concepts An incidence algebra is analogous to a group algebra; in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distributive Lattice
In mathematics, a distributive lattice is a lattice in which the operations of join and meet distribute over each other. The prototypical examples of such structures are collections of sets for which the lattice operations can be given by set union and intersection. Indeed, these lattices of sets describe the scenery completely: every distributive lattice is—up to isomorphism—given as such a lattice of sets. Definition As in the case of arbitrary lattices, one can choose to consider a distributive lattice ''L'' either as a structure of order theory or of universal algebra. Both views and their mutual correspondence are discussed in the article on lattices. In the present situation, the algebraic description appears to be more convenient. A lattice (''L'',∨,∧) is distributive if the following additional identity holds for all ''x'', ''y'', and ''z'' in ''L'': : ''x'' ∧ (''y'' ∨ ''z'') = (''x'' ∧ ''y'') ∨ (''x'' ∧ ''z''). Viewing lattices as partially ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Partially Ordered Set
In mathematics, especially order theory, a partially ordered set (also poset) formalizes and generalizes the intuitive concept of an ordering, sequencing, or arrangement of the elements of a Set (mathematics), set. A poset consists of a set together with a binary relation indicating that, for certain pairs of elements in the set, one of the elements precedes the other in the ordering. The relation itself is called a "partial order." The word ''partial'' in the names "partial order" and "partially ordered set" is used as an indication that not every pair of elements needs to be comparable. That is, there may be pairs of elements for which neither element precedes the other in the poset. Partial orders thus generalize total orders, in which every pair is comparable. Informal definition A partial order defines a notion of Comparability, comparison. Two elements ''x'' and ''y'' may stand in any of four mutually exclusive relationships to each other: either ''x'' ''y'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomas Brylawski
Thomas Henry Brylawski (June 17, 1944 – July 18, 2007) was an American mathematician and professor at the University of North Carolina, Chapel Hill. He worked primarily in matroid theory. Education and career Brylawski was born in 1944, and grew up in Washington, D.C. He attended the Massachusetts Institute of Technology for his undergraduate degree, finishing with a Bachelor of Science in 1966. He then went on to Dartmouth College for his graduate work. He completed his PhD under the direction of Gian-Carlo Rota and Robert Norman in 1970. After his PhD, he moved to the University of North Carolina, Chapel Hill, where he spent the rest of his career. Brylawski was an editor for the ''Proceedings of the American Mathematical Society'' from 1977 until 1989. Brylawski wrote 40 mathematical publications, and advised 6 PhD students. He died in 2007 of esophageal cancer at the Duke Hospice inpatient facility in Hillsborough, North Carolina. Work Brylawski's early work used ideas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
