Logarithmic Concavity and sl2(C)

Logarithmic Concavity and SI2(C)

We observe that for any logarithmically concave nite sequence a 0 , a 1 , : : : , a n of positive integers there is a representation of the Lie algebra sl 2 (C) from which this logarithmic concav-ity follows. Thus, in applying this strategy to prove logarithmic concavity, the only issue is to construct such a representation naturally from given combinatorial data. As an example, we do this when...

h-Vectors of matroids and logarithmic concavity

Article history: Received 11 November 2012 Accepted 4 November 2014 Available online 13 November 2014 Communicated by Ezra Miller MSC: 05B35 52C35

Concavity of Utility, Concavity of Welfare, and Redistribution of Income

The marginal social value of income redistribution is understood to depend on both the concavity of individuals’ utility functions and the concavity of the social welfare function. In the pertinent literatures, notably on optimal income taxation and on normative inequality measurement, it seems to be accepted that the role of these two sources of concavity is symmetric with regard to the social...

Concavity and B-concavity of Solutions of Quasilinear Filtration Equations

Matroids and log-concavity

We show that f -vectors of matroid complexes of realizable matroids are strictly log-concave. This was conjectured by Mason in 1972. Our proof uses the recent result by Huh and Katz who showed that the coefficients of the characteristic polynomial of a realizable matroid form a log-concave sequence. We also prove a statement on log-concavity of h-vectors which strengthens a result by Brown and ...