1,650 research outputs found

    Cohomology and profinite topologies for solvable groups of finite rank

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    Assume GG is a solvable group whose elementary abelian sections are all finite. Suppose, further, that pp is a prime such that GG fails to contain any subgroups isomorphic to CpC_{p^\infty}. We show that if GG is nilpotent, then the pro-pp completion map GG^pG\to \hat{G}_p induces an isomorphism H(G^p,M)H(G,M)H^\ast(\hat{G}_p,M)\to H^\ast(G,M) for any discrete G^p\hat{G}_p-module MM of finite pp-power order. For the general case, we prove that GG contains a normal subgroup NN of finite index such that the map H(N^p,M)H(N,M)H^\ast(\hat{N}_p,M)\to H^\ast(N,M) is an isomorphism for any discrete N^p\hat{N}_p-module MM of finite pp-power order. Moreover, if GG lacks any CpC_{p^\infty}-sections, the subgroup NN enjoys some additional special properties with respect to its pro-pp topology.Comment: This paper supersedes arXiv:1009.2645v5: the two theorems in the introduction to the latter paper are both corollaries to Theorem 1.1 in the present paper. In the second version, Theorem 1.1 is expressed in a slightly more general form than in the first versio

    The quarter-point quadratic isoparametric element as a singular element for crack problems

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    The quadratic isoparametric elements which embody the inverse square root singularity are used for calculating the stress intensity factors at tips of cracks. The strain singularity at a point or an edge is obtained in a simple manner by placing the mid-side nodes at quarter points in the vicinity of the crack tip or an edge. These elements are implemented in NASTRAN as dummy elements. The method eliminates the use of special crack tip elements and in addition, these elements satisfy the constant strain and rigid body modes required for convergence

    A Synthesis of Reinforcement Learning

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    Unified read-write modalities have led to many ex- tensive advances, including SCSI disks and multi-processors. In fact, few electrical engineers would disagree with the investigation of model checking, demonstrates the private importance of artificial in- telligence. We motivate an analysis of write-back caches, which we call Fest

    The strong Atiyah conjecture for right-angled Artin and Coxeter groups

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    We prove the strong Atiyah conjecture for right-angled Artin groups and right-angled Coxeter groups. More generally, we prove it for groups which are certain finite extensions or elementary amenable extensions of such groups.Comment: Minor change
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