arXiv subjects

Alejandro Uribe

Publications and source records attributed to Alejandro Uribe.

23 records · Page 2Linked to original sources

arXiv2003

On the pseudospectra of Berezin-Toeplitz operators

We estimate the norm of the resolvent of non-selfadjoint Berezin Toeplitz operators in the semi-classical limit, under various assumptions on the Poisson bracket of the real and imaginary parts of the symbol. In case this bracket is negative, we symbolically construct pseudomodes well-localized in phase space. We also show that the numerical range converges to the convex hull of the image of the symbol. Our techniques involve the theory of Hermite distributions and classical subelliptic results of Hörmander.

math.SP↗

arXiv2002

The Weyl quantization and the quantum group quantization of the moduli space of flat SU(2)-connections on the torus are the same

We prove that, for the moduli space of flat SU(2)-connections on the torus, the Weyl quantization and the quantization using the quantum group of SL(2,C) are unitarily equivalent. This is done by comparing the matrices of the operators associated by the two quantization to cosine functions. We also discuss the *-product of the Weyl quantization and show that it satisfies the product-to-sum formula for noncommutative cosines on the noncommutative torus.

math-ph↗

arXiv2001

The spectral density function for the Laplacian on high tensor powers of a line bundle

For a symplectic manifold with quantizing line bundle, a choice of almost complex structure determines a Laplacian acting on tensor powers of the bundle. For high tensor powers Guillemin-Uribe showed that there is a well-defined cluster of low-lying eigenvalues, whose distribution is described by a spectral density function. We give an explicit computation of the spectral density function, by constructing certain quasimodes on the associated principle bundle.

math.SP↗

arXiv1998

Nearly Kahlerian Embeddings of Symplectic Manifolds

Given an integral symplectic manifold, we construct a family of "coherent state" maps into complex projective space. The maps are built from sections of the tensor powers of a hermitian line bundle whose curvature is a multiple of the symplectic form. We show that this family is an almost-complex version of the Kodiara embedding. That is, the maps are embeddings which are approximately pseudo-holomorphic.

math.DG↗

arXiv1996

Almost complex structures and geometric quantization

We study two quantization schemes for compact symplectic manifolds with almost complex structures. The first of these is the Spin-c quantization. We prove the analog of Kodaira vanishing for the Spin-c Dirac operator, which shows that the index space of this operator provides an honest (not virtual) vector space semiclassically. We also introduce a new quantization scheme, based on a rescaled Laplacian, for which we are able to prove strong semiclassical properties. The two quantizations are shown to be close semiclassically.

dg-ga↗