39,752 research outputs found

    Counting lifts of Brauer characters

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    In this paper we examine the behavior of lifts of Brauer characters in p-solvable groups where p is an odd prime. In the main result, we show that if \phi \in IBrp(G) is a Brauer character of a solvable group such that \phi has an abelian vertex subgroup Q, then the number of lifts of \phi in Irr(G) is at most |Q|. In order to accomplish this, we develop several results about lifts of Brauer characters in p-solvable groups that were previously only known to be true in the case of groups of odd order.Comment: A different proof of Theorem 1 is in the paper "The number of lifts of Brauer characters with a normal vertex" by J.P. Cossey, M.L.Lewis, and G. Navarro. Hence, we do not expect to try to publish this note. We feel that the proof in this paper is of independent interes

    Lifts and vertex pairs in solvable groups

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    Suppose GG is a pp-solvable group, where pp is odd. We explore the connection between lifts of Brauer characters of GG and certain local objects in GG, called vertex pairs. We show that if χ\chi is a lift, then the vertex pairs of χ\chi form a single conjugacy class. We use this to prove a sufficient condition for a given pair to be a vertex pair of a lift and to study the behavior of lifts with respect to normal subgroups

    Factors affecting the location of payday lending and traditional banking services in North Carolina

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    Payday lending is a relatively new and fast growing segment of the “fringe banking” industry. This paper offers a comparative, descriptive analysis of the location patterns of traditional banks and payday lenders. Utilizing a dataset at the Zip Code Tabulation Area level in North Carolina, we perform negative binomial regressions and find evidence supporting some, but not all common assertions about the location patterns of both types of institutions. A key finding is that after controlling for many covariates, race is still a powerful predictor of the locations of both banks and payday lenders.payday lending, fringe banking, location analysis

    On the Groenewold-Van Hove problem for R^{2n}

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    We discuss the Groenewold-Van Hove problem for R^{2n}, and completely solve it when n = 1. We rigorously show that there exists an obstruction to quantizing the Poisson algebra of polynomials on R^{2n}, thereby filling a gap in Groenewold's original proof without introducing extra hypotheses. Moreover, when n = 1 we determine the largest Lie subalgebras of polynomials which can be unambiguously quantized, and explicitly construct all their possible quantizations.Comment: 15 pages, Latex. Error in the proof of Prop. 3 corrected; minor rewritin

    Length requirements for numerical-relativity waveforms

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    One way to produce complete inspiral-merger-ringdown gravitational waveforms from black-hole-binary systems is to connect post-Newtonian (PN) and numerical-relativity (NR) results to create "hybrid" waveforms. Hybrid waveforms are central to the construction of some phenomenological models for GW search templates, and for tests of GW search pipelines. The dominant error source in hybrid waveforms arises from the PN contribution, and can be reduced by increasing the number of NR GW cycles that are included in the hybrid. Hybrid waveforms are considered sufficiently accurate for GW detection if their mismatch error is below 3% (i.e., a fitting factor about 0.97). We address the question of the length requirements of NR waveforms such that the final hybrid waveforms meet this requirement, considering nonspinning binaries with q = M_2/M_1 \in [1,4] and equal-mass binaries with \chi = S_i/M_i^2 \in [-0.5,0.5]. We conclude that for the cases we study simulations must contain between three (in the equal-mass nonspinning case) and ten (the \chi = 0.5 case) orbits before merger, but there is also evidence that these are the regions of parameter space for which the least number of cycles will be needed.Comment: Corrected some typo
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