Zobrazeno 1 - 10
of 34
pro vyhledávání: '"de Aldecoa, R. Tiedra"'
Autor:
Richard, S., de Aldecoa, R. Tiedra
We present a new technique to obtain polynomial decay estimates for the matrix coefficients of unitary operators. Our approach, based on commutator methods, applies to nets of unitary operators, unitary representations of topological groups, and unit
Externí odkaz:
http://arxiv.org/abs/2109.00108
We perform the scattering analysis of the evolution operator of quantum walks with an anisotropic coin, and we prove a weak limit theorem for their asymptotic velocity. The quantum walks that we consider include one-defect models, two-phase quantum w
Externí odkaz:
http://arxiv.org/abs/1801.02779
We perform the spectral analysis of the evolution operator U of quantum walks with an anisotropic coin, which include one-defect models, two-phase quantum walks, and topological phase quantum walks as special cases. In particular, we determine the es
Externí odkaz:
http://arxiv.org/abs/1703.03488
Autor:
Cecchi, P. A., de Aldecoa, R. Tiedra
We consider in this note Furstenberg transformations on Cartesian products of infinite-dimensional tori. Under some appropriate assumptions, we show that these transformations are uniquely ergodic with respect to the Haar measure and have countable L
Externí odkaz:
http://arxiv.org/abs/1501.06245
Autor:
Richard, S., de Aldecoa, R. Tiedra
For the scattering system given by the Laplacian in a half-space with a periodic boundary condition, we derive resolvent expansions at embedded thresholds, we prove the continuity of the scattering matrix, and we establish new formulas for the wave o
Externí odkaz:
http://arxiv.org/abs/1412.0990
Autor:
Richard, S., de Aldecoa, R. Tiedra
We present an inversion formula which can be used to obtain resolvent expansions near embedded thresholds. As an application, we prove for a class of quantum waveguides the absence of accumulation of eigenvalues and the continuity of the scattering m
Externí odkaz:
http://arxiv.org/abs/1402.0373
Autor:
Richard, S., de Aldecoa, R. Tiedra
In this note, we derive explicit formulas for the Schroedinger wave operators in R^2 under the assumption that 0-energy is neither an eigenvalue nor a resonance. These formulas justify the use of a recently introduced topological approach of scatteri
Externí odkaz:
http://arxiv.org/abs/1212.2230
Autor:
Richard, S., de Aldecoa, R. Tiedra
We prove new and explicit formulas for the wave operators of Schroedinger operators in R^3. These formulas put into light the very special role played by the generator of dilations and validate the topological approach of Levinson's theorem introduce
Externí odkaz:
http://arxiv.org/abs/1210.0143
We present an improved version of commutator methods for unitary operators under a weak regularity condition. Once applied to a unitary operator, the method typically leads to the absence of singularly continuous spectrum and to the local finiteness
Externí odkaz:
http://arxiv.org/abs/1112.0167
Autor:
Richard, S., de Aldecoa, R. Tiedra
We review the spectral analysis and the time-dependent approach of scattering theory for manifolds with asymptotically cylindrical ends. For the spectral analysis, higher order resolvent estimates are obtained via Mourre theory for both short-range a
Externí odkaz:
http://arxiv.org/abs/1108.5018