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Peter T. Johnstone
Peter Tennant Johnstone (born 1948) is Professor of the Foundations of Mathematics at the University of Cambridge, and a fellow of St. John's College. He invented or developed a broad range of fundamental ideas in topos theory. His thesis, completed at the University of Cambridge in 1974, was entitled "Some Aspects of Internal Category Theory in an Elementary Topos In mathematics, a topos (, ; plural topoi or , or toposes) is a category that behaves like the category of sheaves of sets on a topological space (or more generally: on a site). Topoi behave much like the category of sets and possess a notion ...". He is a great-great nephew of the Reverend George Gilfillan who was eulogised in William McGonagall's first poem. Books *. :— " r too hard to read, and not for the faint-hearted"An anonymous referee, as quoted by Johnstone in his ''Sketches of an elephant'', p. ix. *. *. * (v.3 in preparation) References External linksJohnstone's web page* * {{DEF ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Cambridge
, mottoeng = Literal: From here, light and sacred draughts. Non literal: From this place, we gain enlightenment and precious knowledge. , established = , other_name = The Chancellor, Masters and Scholars of the University of Cambridge , type = Public research university , endowment = £7.121 billion (including colleges) , budget = £2.308 billion (excluding colleges) , chancellor = The Lord Sainsbury of Turville , vice_chancellor = Anthony Freeling , students = 24,450 (2020) , undergrad = 12,850 (2020) , postgrad = 11,600 (2020) , city = Cambridge , country = England , campus_type = , sporting_affiliations = The Sporting Blue , colours = Cambridge Blue , website = , logo = University of Cambridge logo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frank Adams
John Frank Adams (5 November 1930 – 7 January 1989) was a British mathematician, one of the major contributors to homotopy theory. Life He was born in Woolwich, a suburb in south-east London, and attended Bedford School. He began research as a student of Abram Besicovitch, but soon switched to algebraic topology. He received his PhD from the University of Cambridge in 1956. His thesis, written under the direction of Shaun Wylie, was titled ''On spectral sequences and self-obstruction invariants''. He held the Fielden Chair of Pure Mathematics, Fielden Chair at the University of Manchester (1964–1970), and became Lowndean Professor of Astronomy and Geometry at the University of Cambridge (1970–1989). He was elected a Fellow of the Royal Society in 1964. His interests included mountaineering—he would demonstrate how to climb right round a table at parties (a Hassler Whitney, Whitney traverse)—and the game of go (game), Go. He died in a car crash in Brampton, Cambr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Category Theory
Category theory is a general theory of mathematical structures and their relations that was introduced by Samuel Eilenberg and Saunders Mac Lane in the middle of the 20th century in their foundational work on algebraic topology. Nowadays, category theory is used in almost all areas of mathematics, and in some areas of computer science. In particular, many constructions of new mathematical objects from previous ones, that appear similarly in several contexts are conveniently expressed and unified in terms of categories. Examples include quotient spaces, direct products, completion, and duality. A category is formed by two sorts of objects: the objects of the category, and the morphisms, which relate two objects called the ''source'' and the ''target'' of the morphism. One often says that a morphism is an ''arrow'' that ''maps'' its source to its target. Morphisms can be ''composed'' if the target of the first morphism equals the source of the second one, and morphism compos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Topos Theory
In mathematics, a topos (, ; plural topoi or , or toposes) is a category that behaves like the category of sheaves of sets on a topological space (or more generally: on a site). Topoi behave much like the category of sets and possess a notion of localization; they are a direct generalization of point-set topology. The Grothendieck topoi find applications in algebraic geometry; the more general elementary topoi are used in logic. The mathematical field that studies topoi is called topos theory. Grothendieck topos (topos in geometry) Since the introduction of sheaves into mathematics in the 1940s, a major theme has been to study a space by studying sheaves on a space. This idea was expounded by Alexander Grothendieck by introducing the notion of a "topos". The main utility of this notion is in the abundance of situations in mathematics where topological heuristics are very effective, but an honest topological space is lacking; it is sometimes possible to find a topos formaliz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Logic
Logic is the study of correct reasoning. It includes both formal and informal logic. Formal logic is the science of deductively valid inferences or of logical truths. It is a formal science investigating how conclusions follow from premises in a topic-neutral way. When used as a countable noun, the term "a logic" refers to a logical formal system that articulates a proof system. Formal logic contrasts with informal logic, which is associated with informal fallacies, critical thinking, and argumentation theory. While there is no general agreement on how formal and informal logic are to be distinguished, one prominent approach associates their difference with whether the studied arguments are expressed in formal or informal languages. Logic plays a central role in multiple fields, such as philosophy, mathematics, computer science, and linguistics. Logic studies arguments, which consist of a set of premises together with a conclusion. Premises and conclusions are usually un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whitehead Prize
The Whitehead Prize is awarded yearly by the London Mathematical Society to multiple mathematicians working in the United Kingdom who are at an early stage of their career. The prize is named in memory of homotopy theory pioneer J. H. C. Whitehead. More specifically, people being considered for the award must be resident in the United Kingdom on 1 January of the award year or must have been educated in the United Kingdom. Also, the candidates must have less than 15 years of work at the postdoctorate level and must not have received any other prizes from the Society. Since the inception of the prize, no more than two could be awarded per year, but in 1999 this was increased to four "to allow for the award of prizes across the whole of mathematics, including applied mathematics, mathematical physics, and mathematical aspects of computer science". The Senior Whitehead Prize has similar residence requirements and rules concerning prior prizes, but is intended to recognize more exp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foundations Of Mathematics
Foundations of mathematics is the study of the philosophy, philosophical and logical and/or algorithmic basis of mathematics, or, in a broader sense, the mathematical investigation of what underlies the philosophical theories concerning the nature of mathematics. In this latter sense, the distinction between foundations of mathematics and philosophy of mathematics turns out to be quite vague. Foundations of mathematics can be conceived as the study of the basic mathematical concepts (set, function, geometrical figure, number, etc.) and how they form hierarchies of more complex structures and concepts, especially the fundamentally important structures that form the language of mathematics (formulas, theories and their model theory, models giving a meaning to formulas, definitions, proofs, algorithms, etc.) also called metamathematics, metamathematical concepts, with an eye to the philosophical aspects and the unity of mathematics. The search for foundations of mathematics is a cent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Topos Theory
In mathematics, a topos (, ; plural topoi or , or toposes) is a category that behaves like the category of sheaves of sets on a topological space (or more generally: on a site). Topoi behave much like the category of sets and possess a notion of localization; they are a direct generalization of point-set topology. The Grothendieck topoi find applications in algebraic geometry; the more general elementary topoi are used in logic. The mathematical field that studies topoi is called topos theory. Grothendieck topos (topos in geometry) Since the introduction of sheaves into mathematics in the 1940s, a major theme has been to study a space by studying sheaves on a space. This idea was expounded by Alexander Grothendieck by introducing the notion of a "topos". The main utility of this notion is in the abundance of situations in mathematics where topological heuristics are very effective, but an honest topological space is lacking; it is sometimes possible to find a topos formaliz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Category
In mathematics, more specifically in category theory, internal categories are a generalisation of the notion of small category, and are defined with respect to a fixed ambient category. If the ambient category is taken to be the category of sets then one recovers the theory of small categories. In general, internal categories consist of a pair of objects in the ambient category—thought of as the 'object of objects' and 'object of morphisms'—together with a collection of morphisms in the ambient category satisfying certain identities. Group objects, are common examples of internal categories. There are notions of internal functors and natural transformations that make the collection of internal categories in a fixed category into a 2-category. Definitions Let C be a category with pullbacks. An internal category in C consists of the following data: two C-objects C_0,C_1 named "object of objects" and "object of morphisms" respectively and four C-arrows d_0,d_1:C_1\rightarrow C_0, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elementary Topos
In mathematics, a topos (, ; plural topoi or , or toposes) is a category that behaves like the category of sheaves of sets on a topological space (or more generally: on a site). Topoi behave much like the category of sets and possess a notion of localization; they are a direct generalization of point-set topology. The Grothendieck topoi find applications in algebraic geometry; the more general elementary topoi are used in logic. The mathematical field that studies topoi is called topos theory. Grothendieck topos (topos in geometry) Since the introduction of sheaves into mathematics in the 1940s, a major theme has been to study a space by studying sheaves on a space. This idea was expounded by Alexander Grothendieck by introducing the notion of a "topos". The main utility of this notion is in the abundance of situations in mathematics where topological heuristics are very effective, but an honest topological space is lacking; it is sometimes possible to find a topos formal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Gilfillan
__NOTOC__ Rev George Gilfillan (30 January 1813 – 13 August 1878) was a Scottish author and poet. One of the spasmodic poets, Gilfillan was also an editor and commentator, with memoirs, critical dissertations in many editions of earlier British poetry. Early life and education George Gilfillan was born at Comrie, Perthshire, the eleventh of twelve children. His father, the Rev. Samuel Gilfillan, the author of some theological works, was for many years minister of a Secession congregation. His mother, Rachel Barlas, the daughter of another Secession minister, was a notable beauty often spoken of as "The Star of the North". In 1825 he went to study at the University of Glasgow, where his classmates included John Eadie, William Hanna and Archibald Campbell Tait, the future Archbishop of Canterbury. In 1833 he studied for a year in Mid Calder before moving on to Edinburgh where he received warm encouragement from the professor of moral philosophy, John Wilson, better known as Chri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William McGonagall
William Topaz McGonagall (March 1825 – 29 September 1902) was a Scottish poet of Irish descent. He gained notoriety as an extremely bad poet who exhibited no recognition of, or concern for, his peers' opinions of his work. He wrote about 200 poems, including "The Tay Bridge Disaster" and "The Famous Tay Whale", which are widely regarded as some of the worst in English literature. Groups throughout Scotland engaged him to make recitations from his work, and contemporary descriptions of these performances indicate that many listeners were appreciating McGonagall's skill as a comic music hall character. Collections of his verse remain popular, with several volumes available today. McGonagall has been lampooned as the worst poet in British history. The chief criticisms are that he was deaf to poetic metaphor and unable to scan correctly. His only apparent understanding of poetry was his belief that it needed to rhyme. McGonagall's fame stems from the humorous effects these shor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
