Zobrazeno 1 - 10
of 121
pro vyhledávání: '"Graffi, Sandro"'
Autor:
Caliceti, Emanuela, Graffi, Sandro
A class of non-selfadjoint, $\PT$-symmetric operators is identified similar to a self-adjoint one, thus entailing the reality of the spectrum. The similarity transformation is explicitly constructed through the method of the quantum normal form, whos
Externí odkaz:
http://arxiv.org/abs/1206.0582
It is established that a PT-symmetric elliptic quadratic differential operator with real spectrum is similar to a self-adjoint operator precisely when the associated fundamental matrix has no Jordan blocks.
Comment: In the revised version, the m
Comment: In the revised version, the m
Externí odkaz:
http://arxiv.org/abs/1204.6605
Autor:
Graffi, Sandro, Paul, Thierry
We consider the Schr\"odinger operator defined by the quantization of the linear flow of diophantine frequencies over the l-dimensional torus, perturbed by a holomorphic potential which depends on the actions only through their particular linear comb
Externí odkaz:
http://arxiv.org/abs/1102.0942
Autor:
Graffi, Sandro, Zanelli, Lorenzo
We construct a family of Fourier Integral Operators, defined for arbitrary large times, representing a global parametrix for the Schr\"odinger propagator when the potential is quadratic at infinity. This construction is based on the geometric approac
Externí odkaz:
http://arxiv.org/abs/1006.1753
Publikováno v:
SIGMA 6 (2010), 009, 8 pages
We prove the reality of the perturbed eigenvalues of some PT symmetric Hamiltonians of physical interest by means of stability methods. In particular we study 2-dimensional generalized harmonic oscillators with polynomial perturbation and the one-dim
Externí odkaz:
http://arxiv.org/abs/1001.3656
Publikováno v:
J. Phys. A: Math. Theor. 43 (2010) 032001
The evolution of a quantum system subjected to infinitely many measurements in a finite time interval is confined in a proper subspace of the Hilbert space. This phenomenon is called "quantum Zeno effect": a particle under intensive observation does
Externí odkaz:
http://arxiv.org/abs/0911.5675
The spectrum of a one-parameter family of signed transfer operators associated to the Farey map is studied in detail. We show that when acting on a suitable Hilbert space of analytic functions they are self-adjoint and exhibit absolutely continuous s
Externí odkaz:
http://arxiv.org/abs/0708.0686
Autor:
Blas, Carlos Villegas, Graffi, Sandro
Consider in $L^2(\R^2)$ the operator family $H(\epsilon):=P_0(\hbar,\omega)+\epsilon F_0$. $P_0$ is the quantum harmonic oscillator with diophantine frequency vector $\om$, $F_0$ a bounded pseudodifferential operator with symbol decreasing to zero at
Externí odkaz:
http://arxiv.org/abs/math-ph/0702021
We present a new proof of the convergence of the N-particle Schroedinger dynamics for bosons towards the dynamics generated by the Hartree equation in the mean-field limit. For a restricted class of two-body interactions, we obtain convergence estima
Externí odkaz:
http://arxiv.org/abs/math-ph/0603055