منابع مشابه
Generalizations of Hedberg's Theorem
As the groupoid interpretation by Hofmann and Streicher shows, uniqueness of identity proofs (UIP) is not provable. Generalizing a theorem by Hedberg, we give new characterizations of types that satisfy UIP. It turns out to be natural in this context to consider constant endofunctions. For such a function, we can look at the type of its fixed points. We show that this type has at most one eleme...
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Wei’s celebrated Duality Theorem is generalized in several ways, expressed as duality theorems for linear codes over division rings and, more generally, duality theorems for matroids. These results are further generalized, resulting in two Wei-type duality theorems for new combinatorial structures that are introduced and named demi-matroids. These generalize matroids and are the appropriate com...
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New eigenvalue inclusion regions are given by establishing the necessary and sufficient conditions for two classes of nonsingular matrices, named double α1-matrices and double α2-matrices. These results are generalizations of Brauer’s eigenvalue localization theorem and improvements over the results in [L. Cvetković, V. Kostić, R. Bru, and F. Pedroche. A simple generalization of Geršgorin’s the...
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These notes are based on the Number Theory seminar I gave at Purdue University on September 19, 2013 titled “Hilbert’s theorem 90 and generalization”. The proof of Hilbert’s 90 is taken from an answer I found on MathOverflow at http://mathoverflow.net/a/21117. In the seminar, Professor Goins asked an interesting question about the isomorphism classes of rank one tori which I have blogged here. ...
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Our topic traces back to DEMING AND STEPHAN [1] who sought to reconcile an empirical joint distribution of two random variables with a priori known marginals for each and proposed an iterative scheme for determining a solution. Thus, in the case of finite probability spaces, the problem data consist of two probability vectors p0 and p1 together with the empirical joint probability matrix P = [p...
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ژورنال
عنوان ژورنال: Matematychni Studii
سال: 2017
ISSN: 1027-4634
DOI: 10.15330/ms.47.1.91-99