- published: 11 Oct 2013
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In abstract algebra, the free monoid on a set is the monoid whose elements are all the finite sequences (or strings) of zero or more elements from that set, with string concatenation as the monoid operation and with the unique sequence of zero elements, often called the empty string and denoted by ε or λ, as the identity element. The free monoid on a set A is usually denoted A∗. The free semigroup on A is the subsemigroup of A∗ containing all elements except the empty string. It is usually denoted A+.
More generally, an abstract monoid (or semigroup) S is described as free if it is isomorphic to the free monoid (or semigroup) on some set.
As the name implies, free monoids and semigroups are those objects which satisfy the usual universal property defining free objects, in the respective categories of monoids and semigroups. It follows that every monoid (or semigroup) arises as a homomorphic image of a free monoid (or semigroup). The study of semigroups as images of free semigroups is called combinatorial semigroup theory.
The Cahn–Hilliard equation (after John W. Cahn and John E. Hilliard) is an equation of mathematical physics which describes the process of phase separation, by which the two components of a binary fluid spontaneously separate and form domains pure in each component. If is the concentration of the fluid, with indicating domains, then the equation is written as
where is a diffusion coefficient with units of and gives the length of the transition regions between the domains. Here is the partial time derivative and is the Laplacian in dimensions. Additionally, the quantity is identified as a chemical potential.
Related to it is the Allen–Cahn equation, as well as the Stochastic Cahn–Hilliard Equation and the Stochastic Allen–Cahn equation.
Of interest to mathematicians is the existence of a unique solution of the Cahn–Hilliard equation, given by smooth initial data. The proof relies essentially on the existence of a Lyapunov functional. Specifically, if we identify
Complete set of Video Lessons and Notes available only at http://www.studyyaar.com/index.php/module/1-algebraic-structures-groups-and-rings n-ary operation, Algeraic System, Binary Operations, Semi-Group, Residue Class Modulo n, Identity, Monoid http://www.studyyaar.com/index.php/module-video/watch/81-algebraic-system-basic-concepts-semi-group-identity-element-and-monoids
We use techniques from geometric group theory and from low dimensional topology to study the structure of sets of solutions to systems of equations (varieties) over a free semigroup.
Basic Algebraic Geometry: In this part, we introduce Spec(R) and affine semigroups. This allows us to give yet another characterization of affine toric varieties in terms of affine semigroups.
In this talk, we will discuss existence and uniqueness of solutions to the viscous Cahn-Hilliard equation. This is a system of two partial differential equations, which can be seen as an interpolation between the Allen-Cahn equation and the Cahn-Hilliard equation. Although the interest in this problem is motivated by the physical processes that are modeled by these equations, the purpose they'll serve for the talk is to provide a context to introduce some of the techniques one can use to tackle evolutionary problems. In particular, I will show how the theory of analytic semigroups and ODEs in Banach spaces can be applied to the study of PDEs.
Find this video and other talks given by worldwide mathematicians on CIRM's Audiovisual Mathematics Library: http://library.cirm-math.fr. And discover all its functionalities: - Chapter markers and keywords to watch the parts of your choice in the video - Videos enriched with abstracts, bibliographies, Mathematics Subject Classification - Multi-criteria search by author, title, tags, mathematical area I will discuss recent progress on understanding the dimension of self-similar sets and measures. The main conjecture in this field is that the only way that the dimension of such a fractal can be "non-full" is if the semigroup of contractions which define it is not free. The result I will discuss is that "non-full" dimension implies "almost non-freeness", in the sense that there are distinc...
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We use techniques from geometric group theory and from low dimensional topology to study the structure of sets of solutions to systems of equations (varieties) over a free semigroup.
"We've all seen them on the corner of our local software development neighborhoods: FP purists, shamelessly peddling scalaz to unsuspecting developers. Lured in by promises of Free Monoids, Semigroups, and Endofunctors these developers soon seem lost in throes of ecstatic coding. "To the skeptical and stubbornly practical among us, the above might ring a little true – especially if read in Rob Serling's voice. Images of gibbering horrors lurking in the depths of mathematical perfection swim before our eyes.But what if there is true value in the world of scalaz? What if it is possible to use these tools for good (and a little bit of evil – it's fun to use learning for evil!) and profit... Without getting hopelessly lost in the opium dens of FP?In this talk we will look at some of the "gatew...
We've all seen them on the corner of our local software development neighborhoods: FP purists, shamelessly peddling scalaz to unsuspecting developers. Lured in by promises of Free Monoids, Semigroups, and Endofunctors these developers soon seem lost in throes of ecstatic coding. To the skeptical and stubbornly practical among us, the above might ring a little true – especially if read in Rod Serling's voice. Images of gibbering horrors lurking in the depths of mathematical perfection swim before our eyes. But what if there is true value in the world of Scalaz? What if it is possible to use these tools for good (and a little bit of evil – it's fun to use learning for evil!) and profit... Without getting hopelessly lost in the opium dens of FP? In this talk we will look at some of the "gatew...
By, Brendan McAdams We've all seen them on the corner of our local software development neighborhoods: FP purists, shamelessly peddling scalaz to unsuspecting developers. Lured in by promises of Free Monoids, Semigroups, and Endofunctors these developers soon seem lost in throes of ecstatic coding. To the skeptical and stubbornly practical among us, the above might ring a little true – especially if read in Rob Serling's voice. Images of gibbering horrors lurking in the depths of mathematical perfection swim before our eyes. But what if there is true value in the world of scalaz? What if it is possible to use these tools for good (and a little bit of evil – it's fun to use learning for evil!) and profit... Without getting hopelessly lost in the opium dens of FP? In this talk we will lo...
Read your free e-book: http://hotaudiobook.com/mebk/50/en/B0116WHLM0/book This book discusses recent developments in semigroup theory and its applications in areas such as operator algebras, operator approximations and category theory. All contributing authors are eminent researchers in their respective fields, from across the world. Their papers, presented at the 2014 International Conference on Semigroups, Algebras and Operator Theory in Cochin, India, focus on recent developments in semigroup theory and operator algebras. They highlight current research activities on the structure theory of semigroups as well as the role of semigroup theoretic approaches to other areas such as rings and algebras. The deliberations and discussions at the conference point to future research directions in ...
Find this video and other talks given by worldwide mathematicians on CIRM's Audiovisual Mathematics Library: http://library.cirm-math.fr. And discover all its functionalities: - Chapter markers and keywords to watch the parts of your choice in the video - Videos enriched with abstracts, bibliographies, Mathematics Subject Classification - Multi-criteria search by author, title, tags, mathematical area I will discuss recent progress on understanding the dimension of self-similar sets and measures. The main conjecture in this field is that the only way that the dimension of such a fractal can be "non-full" is if the semigroup of contractions which define it is not free. The result I will discuss is that "non-full" dimension implies "almost non-freeness", in the sense that there are distinc...
Read your free e-book: http://hotaudiobook.com/mebk/50/en/B000QCQX3A/book In recent years, it has become increasingly clear that there are important connections relating three conceptsgroupoids, inverse semigroups, and operator algebras. There has been a great deal of progress in this area over the last two decades, and this book gives a careful, up-to-date and reasonably extensive account of the subject matter. After an introductory first chapter, the second chapter presents a self-contained account of inverse semigroups, locally compact and r-discrete groupoids, and Lie groupoids. The section on Lie groupoids in chapter 2 contains a detailed discussion of groupoids particularly important in noncommutative geometry, including the holonomy groupoids of a foliated manifold and the tangent g...
Quantale In mathematics, quantales are certain partially ordered algebraic structures that generalize locales (point free topologies) as well as various multiplicative lattices of ideals from ring theory and functional analysis (C*-algebras, von Neumann algebras).Quantales are sometimes referred to as complete residuated semigroups. -Video is targeted to blind users Attribution: Article text available under CC-BY-SA image source in video https://www.youtube.com/watch?v=qtPFsmuII7w
Read your free e-book: http://easyget.us/mebk/50/en/B000PY3SCI/book The study of the connections between mathematical automata and for mal logic is as old as theoretical computer science itself. In the founding paper of the subject, published in 1936, Turing showed how to describe the behavior of a universal computing machine with a formula of first order predicate logic, and thereby concluded that there is no algorithm for deciding the validity of sentences in this logic. Research on the log ical aspects of the theory of finite-state automata, which is the subject of this book, began in the early 1960's with the work of J. Richard Biichi on monadic second-order logic. Biichi's investigations were extended in several directions. One of these, explored by Mcnaughton and Papert in their 1971...
First video regarding algebraic automata theory. It goes into subautomata, semigroups, and free semigroups Book used, Abraham Ginzburg, algebraic automata theory http://www.amazon.com/gp/offer-listing/0122850505/ref=dp_olp_all_mbc?ie=UTF8&condition;=all