Finite sample properties of random covariance-type matrices have been the subject of much research. In this paper we focus on the 'lower tail' of such a matrix, and prove that it is subgaussian under a simple fourth moment assumption on the one-dimensional marginals of the random vectors. A similar result holds for more general sums of random po...
Creator:
Oliveira, Roberto Imbuzeiro (Institute of Pure and Applied Mathematics (IMPA))
Created:
2015-04-17
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
We study contraction under a Markov semi-group and influence bounds for functions all of whose low level Fourier coefficients vanish. This study is motivated by the explicit construction of 3-regular expander graphs of Mendel and Naor, though our results have no direct implication for the construction of expander graphs. In the positive directio...
Creator:
Heilman, Steven (University of California, Los Angeles)
Created:
2015-04-28
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
