471 research outputs found
Fluctuations of Rectangular Young Diagrams of Interlacing Wigner Eigenvalues
We prove a new CLT for the difference of linear eigenvalue statistics of a
Wigner random matrix and its minor and find that the fluctuation
is much smaller than the fluctuations of the individual linear statistics, as a
consequence of the strong correlation between the eigenvalues of and . In particular our theorem identifies the fluctuation of Kerov's rectangular
Young diagrams, defined by the interlacing eigenvalues of and ,
around their asymptotic shape, the Vershik-Kerov-Logan-Shepp curve. This result
demonstrates yet another aspect of the close connection between random matrix
theory and Young diagrams equipped with the Plancherel measure known from
representation theory. For the latter a CLT has been obtained in [18] which is
structurally similar to our result but the variance is different, indicating
that the analogy between the two models has its limitations. Moreover, our
theorem shows that Borodin's result [7] on the convergence of the spectral
distribution of Wigner matrices to a Gaussian free field also holds in
derivative sense.Comment: New citations and appendix added. 24 pages, 2 figures. Updated
numbering to match the published versio
Phase Transition in the Density of States of Quantum Spin Glasses
We prove that the empirical density of states of quantum spin glasses on
arbitrary graphs converges to a normal distribution as long as the maximal
degree is negligible compared with the total number of edges. This extends the
recent results of [6] that were proved for graphs with bounded chromatic number
and with symmetric coupling distribution. Furthermore, we generalise the result
to arbitrary hypergraphs. We test the optimality of our condition on the
maximal degree for -uniform hypergraphs that correspond to -spin glass
Hamiltonians acting on distinguishable spin- particles. At the
critical threshold we find a sharp classical-quantum phase
transition between the normal distribution and the Wigner semicircle law. The
former is characteristic to classical systems with commuting variables, while
the latter is a signature of noncommutative random matrix theory.Comment: 21 pages, 2 figure
The Linear Boltzmann Equation as the Low Density Limit of a Random Schrodinger Equation
We study the evolution of a quantum particle interacting with a random
potential in the low density limit (Boltzmann-Grad). The phase space density of
the quantum evolution defined through the Husimi function converges weakly to a
linear Boltzmann equation with collision kernel given by the full quantum
scattering cross section.Comment: 74 pages, 4 figures, (Final version -- typos corrected
Bounds on the norm of Wigner-type random matrices
We consider a Wigner-type ensemble, i.e. large hermitian random
matrices with centered independent entries and with a general matrix of
variances . The norm of is asymptotically given
by the maximum of the support of the self-consistent density of states. We
establish a bound on this maximum in terms of norms of powers of that
substantially improves the earlier bound given in
[arXiv:1506.05098]. The key element of the proof is an effective Markov chain
approximation for the contributions of the weighted Dyck paths appearing in the
iterative solution of the corresponding Dyson equation.Comment: 25 pages, 8 figure
Random Matrices with Slow Correlation Decay
We consider large random matrices with a general slowly decaying correlation
among its entries. We prove universality of the local eigenvalue statistics and
optimal local laws for the resolvent away from the spectral edges, generalizing
the recent result of [arXiv:1604.08188] to allow slow correlation decay and
arbitrary expectation. The main novel tool is a systematic diagrammatic control
of a multivariate cumulant expansion.Comment: 41 pages, 1 figure. We corrected a typo in (4.1b
Cusp Universality for Random Matrices I: Local Law and the Complex Hermitian Case
For complex Wigner-type matrices, i.e. Hermitian random matrices with
independent, not necessarily identically distributed entries above the
diagonal, we show that at any cusp singularity of the limiting eigenvalue
distribution the local eigenvalue statistics are universal and form a Pearcey
process. Since the density of states typically exhibits only square root or
cubic root cusp singularities, our work complements previous results on the
bulk and edge universality and it thus completes the resolution of the
Wigner-Dyson-Mehta universality conjecture for the last remaining universality
type in the complex Hermitian class. Our analysis holds not only for exact
cusps, but approximate cusps as well, where an extended Pearcey process
emerges. As a main technical ingredient we prove an optimal local law at the
cusp for both symmetry classes. This result is also used in the companion paper
[arXiv:1811.04055] where the cusp universality for real symmetric Wigner-type
matrices is proven.Comment: 58 pages, 2 figures. Updated introduction and reference
On a Failed Defense of Factory Farming
Timothy Hsiao attempts to defend industrial animal farming by arguing that it is not inherently cruel. We raise three main objections to his defense. First, his argument rests on a misunderstanding of the nature of cruelty. Second, his conclusion, though technically true, is so weak as to be of virtually no moral significance or interest. Third, his contention that animals lack moral standing, and thus that mistreating them is wrong only insofar as it makes one more disposed to mistreat other humans, is untenable on both philosophical and biological grounds
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