41,551 research outputs found

    On Topological Structure of the First Non-abelian Cohomology of Topological Groups

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    Let GG, RR and AA be topological groups. Suppose that GG and RR act continuously on AA, and GG acts continuously on RR. In this paper, we define a partially crossed topological Gβˆ’RG-R-bimodule (A,ΞΌ)(A,\mu), where ΞΌ:Aβ†’R\mu:A\rightarrow R is a continuous homomorphism. Let Derc(G,(A,ΞΌ))Der_{c}(G,(A,\mu)) be the set of all (Ξ±,r)(\alpha,r) such that Ξ±:Gβ†’A\alpha:G\rightarrow A is a continuous crossed homomorphism and ΞΌΞ±(g)=rgrβˆ’1\mu\alpha(g)=r^{g}r^{-1}. We introduce a topology on Derc(G,(A,ΞΌ))Der_{c}(G,(A,\mu)). We show that Derc(G,(A,ΞΌ))Der_{c}(G,(A,\mu)) is a topological group, wherever GG and RR are locally compact. We define the first cohomology, H1(G,(A,ΞΌ))H^{1}(G,(A,\mu)), of GG with coefficients in (A,ΞΌ)(A,\mu) as a quotient space of Derc(G,(A,ΞΌ))Der_{c}(G,(A,\mu)). Also, we state conditions under which H1(G,(A,ΞΌ))H^{1}(G,(A,\mu)) is a topological group. Finally, we show that under what conditions H1(G,(A,ΞΌ))H^{1}(G,(A,\mu)) is one of the following: kk-space, discrete, locally compact and compact.Comment: 15 page

    Standard Projective Simplicial Kernels and the Second Abelian Cohomology of Topological Groups

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    Let AA be an abelian topological GG-module. We give an interpretion for the second cohomology, H2(G,A)H^{2}(G,A), of GG with coefficients in AA. As a result we show that if PP is a projective topological group, then H2(P,A)=0H^{2}(P,A)=0 for every abelian topological PP-module AA.Comment: 12 page

    First Non-abelian Cohomology of Topological Groups II

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    In this paper we introduce a new definition of the first non-abelian cohomology of topological groups. We relate the cohomology of a normal subgroup NN of a topological group GG and the quotient G/NG/N to the cohomology of GG. We get the inflation-restriction exact sequence. Also, we obtain a seven-term exact cohomology sequence up to dimension 2. We give an interpretation of the first non-abelian cohomology of a topological group by the notion of a principle homogeneous space.Comment: 18 page

    SUT System Description for NIST SRE 2016

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    This paper describes the submission to fixed condition of NIST SRE 2016 by Sharif University of Technology (SUT) team. We provide a full description of the systems that were included in our submission. We start with an overview of the datasets that were used for training and development. It is followed by describing front-ends which contain different VAD and feature types. UBM and i-vector extractor training are the next details in this paper. As one of the important steps in system preparation, preconditioning the i-vectors are explained in more details. Then, we describe the classifier and score normalization methods. And finally, some results on SRE16 evaluation dataset are reported and analyzed.Comment: Presented in NIST SRE 2016 Evaluation Worksho

    On Dynamics of Brans--Dicke Theory of Gravitation

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    We study longstanding problem of cosmological clock in the context of Brans-Dicke theory of gravitation. We present the Hamiltonian formulation of the theory for a class of spatially homogenous cosmological models. Then, we show that formulation of the Brans-Dicke theory in the Einstein frame allows how an identification of an appropriate cosmological time variable, as a function of the scalar field in the theory, can be emerged in quantum cosmology. The classical and quantum results are applied to the Friedmann-Robertson-Walker cosmological models.Comment: 15 page

    New Methods for Solving Large Scale Linear Programming Problems in the Windows and Linux computer operating systems

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    In this study, calculations necessary to solve the large scale linear programming problems in two operating systems, Linux and Windows 7 (Win), are compared using two different methods. Relying on the interior-point methods, linear-programming interior point solvers (LIPSOL) software was used for the first method and relying on an augmented Lagrangian method-based algorithm, the second method used the generalized derivative. The performed calculations for various problems show the produced random in the Linux operating system (OS) and Win OS indicate the efficiency of the performed calculations in the Linux OS in terms of the accuracy and using of the optimum memory.Comment: 8 pages; This paper will be published in Appl. Math. Inf. Sci. Vol. 7 No. 1 (2013

    Big Handlebody Distance Implies Finite Mapping Class Group

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    We show that if MM is a closed three manifold with a Heegaard splitting with sufficiently big "handlebody distance" then the subgroup of the mapping class group of the Heegaard surface, which extend to both handlebodies is finite. As a corollary, this implies that under the same hypothesis, the mapping class group of MM is finite.Comment: 9 page

    Modular-type functions attached to mirror quintic Calabi-Yau varieties

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    In this article we study a differential algebra of modular-type functions attached to the periods of a one parameter family of Calabi-Yau varieties which is mirror dual to the universal family of quintic threefolds. Such an algebra is generated by seven functions satisfying functional and differential equations in parallel to the modular functional equations of classical Eisenstein series and the Ramanujan differential equation. Our result is the first example of automorphic-type functions attached to varieties whose period domain is not Hermitian symmetric. It is a reformulation and realization of a problem of Griffiths around seventies on the existence of automorphic functions for the moduli of polarized Hodge structures

    Primitive ideal space of Higher-rank graph Cβˆ—C^*-algebras and decomposability

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    In this paper, we describe primitive ideal space of the Cβˆ—C^*-algebra Cβˆ—(Ξ›)C^*(\Lambda) associated to any locally convex row-finite kk-graph Ξ›\Lambda. To do this, we will apply the Farthing's desourcifying method on a recent result of Carlsen, Kang, Shotwell, and Sims. We also characterize certain maximal ideals of Cβˆ—(Ξ›)C^*(\Lambda). Furthermore, we study the decomposability of Cβˆ—(Ξ›)C^*(\Lambda). We apply the description of primitive ideals to show that if II is a direct summand of Cβˆ—(Ξ›)C^*(\Lambda), then it is gauge-invariant and isomorphic to a certain kk-graph Cβˆ—C^*-algebra. So, we may characterize decomposable higher-rank Cβˆ—C^*-algebras by giving necessary and sufficient conditions for the underlying kk-graphs. Moreover, we determine all such Cβˆ—C^*-algebras which can be decomposed into a direct sum of finitely many indecomposable Cβˆ—C^*-algebras.Comment: The last versio

    Spoken Pass-Phrase Verification in the i-vector Space

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    The task of spoken pass-phrase verification is to decide whether a test utterance contains the same phrase as given enrollment utterances. Beside other applications, pass-phrase verification can complement an independent speaker verification subsystem in text-dependent speaker verification. It can also be used for liveness detection by verifying that the user is able to correctly respond to a randomly prompted phrase. In this paper, we build on our previous work on i-vector based text-dependent speaker verification, where we have shown that i-vectors extracted using phrase specific Hidden Markov Models (HMMs) or using Deep Neural Network (DNN) based bottle-neck (BN) features help to reject utterances with wrong pass-phrases. We apply the same i-vector extraction techniques to the stand-alone task of speaker-independent spoken pass-phrase classification and verification. The experiments on RSR2015 and RedDots databases show that very simple scoring techniques (e.g. cosine distance scoring) applied to such i-vectors can provide results superior to those previously published on the same data
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