1,100,174 research outputs found
Period polynomials and Ihara brackets
Schneps [J. Lie Theory 16 (2006), 19--37] has found surprising links between
Ihara brackets and even period polynomials. These results can be recovered and
generalized by considering some identities relating Ihara brackets and
classical Lie brackets. The period polynomials generated by this method are
found to be essentially the Kohnen-Zagier polynomials.Comment: 12 pages, LaTE
Convex Sobolev inequalities and spectral gap
This note is devoted to the proof of convex Sobolev (or generalized
Poincar\'{e}) inequalities which interpolate between spectral gap (or
Poincar\'{e}) inequalities and logarithmic Sobolev inequalities. We extend to
the whole family of convex Sobolev inequalities results which have recently
been obtained by Cattiaux and Carlen and Loss for logarithmic Sobolev
inequalities. Under local conditions on the density of the measure with respect
to a reference measure, we prove that spectral gap inequalities imply all
convex Sobolev inequalities with constants which are uniformly bounded in the
limit approaching the logarithmic Sobolev inequalities. We recover the case of
the logarithmic Sobolev inequalities as a special case
Survival probability of the branching random walk killed below a linear boundary
We give an alternative proof of a result by N. Gantert, Y. Hu and Z. Shi on
the asymptotic behavior of the survival probability of the branching random
walk killed below a linear boundary, in the special case of deterministic
binary branching and bounded random walk steps. Connections with the
Brunet-Derrida theory of stochastic fronts are discussed
Towards a pivotal-based approach for business process alignment.
This article focuses on business process engineering, especially on alignment between business analysis and implementation. Through a business process management approach, different transformations interfere with process models in order to make them executable. To keep the consistency of process model from business model to IT model, we propose a pivotal metamodel-centric methodology. It aims at keeping or giving all requisite structural and semantic data needed to perform such transformations without loss of information. Through this we can ensure the alignment between business and IT. This article describes the concept of pivotal metamodel and proposes a methodology using such an approach. In addition, we present an example and the resulting benefits
Must-Take Cards: Merchant Discounts and Avoided Costs
Antitrust authorities often argue that merchants cannot reasonably turn down payment cards and therefore must accept excessively high merchant discounts. The paper
attempts to shed light on this “must-take cards” view from two angles.
First, the paper gives some operational content to the notion of “must-take card” through the “avoided-cost test” or “tourist test”: would the merchant want to refuse a
card payment when a non-repeat customer with enough cash in her pocket is about to pay at the cash register? It analyzes its relevance as an indicator of excessive interchange fees.
Second, it identifies four key sources of potential social biases in the payment card systems’ determination of interchange fees: internalization by merchants of a fraction of cardholder surplus, issuers’ per-transaction markup, merchant heterogeneity, and extent of cardholder multi-homing. It compares the industry and social optima both in the short term (fixed number of issuers) and the long term (in which issuer offerings and entry
respond to profitability)
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