137 research outputs found

    Mathematics discovered, invented, and inherited

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    The classical platonist/formalist dilemma in philosophy of mathematics can be expressed in lay terms as a deceptively naive question: is new mathematics discovered or invented? Using an example from my own mathematical life, I argue that there is also a third way: new mathematics can also be inherited -- and in the process briefly discuss a remarkable paper by W. Burnside of 1900.Comment: Version 2: A few references have been added http://www.borovik.net/selecta

    Black Box White Arrow

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    The present paper proposes a new and systematic approach to the so-called black box group methods in computational group theory. Instead of a single black box, we consider categories of black boxes and their morphisms. This makes new classes of black box problems accessible. For example, we can enrich black box groups by actions of outer automorphisms. As an example of application of this technique, we construct Frobenius maps on black box groups of untwisted Lie type in odd characteristic (Section 6) and inverse-transpose automorphisms on black box groups encrypting (P)SLn(Fq){\rm (P)SL}_n(\mathbb{F}_q). One of the advantages of our approach is that it allows us to work in black box groups over finite fields of big characteristic. Another advantage is explanatory power of our methods; as an example, we explain Kantor's and Kassabov's construction of an involution in black box groups encrypting SL2(2n){\rm SL}_2(2^n). Due to the nature of our work we also have to discuss a few methodological issues of the black box group theory. The paper is further development of our text "Fifty shades of black" [arXiv:1308.2487], and repeats parts of it, but under a weaker axioms for black box groups.Comment: arXiv admin note: substantial text overlap with arXiv:1308.248

    Construction of Curtis-Phan-Tits system in black box classical groups

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    We present a polynomial time Monte-Carlo algorithm for finite simple black box classical groups of odd characteristic which constructs all root SL2(q){\rm{SL}}_2(q)-subgroups associated with the nodes of the extended Dynkin diagram of the corresponding algebraic group.Comment: 35 page
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