IRIS Università degli Studi di Bolognahttps://cris.unibo.itIl sistema di repository digitale IRIS acquisisce, archivia, indicizza, conserva e rende accessibili prodotti digitali della ricerca.Thu, 21 Jan 2021 12:11:56 GMT2021-01-21T12:11:56Z10321On the Thermodynamic Limit for Spin Glasseshttp://hdl.handle.net/11585/27378Titolo: On the Thermodynamic Limit for Spin Glasses
Thu, 01 Jan 2004 00:00:00 GMThttp://hdl.handle.net/11585/273782004-01-01T00:00:00ZPerturbation theory of PT-symmetric Hamiltonianshttp://hdl.handle.net/11585/37145Titolo: Perturbation theory of PT-symmetric Hamiltonians
Abstract: In the framework of perturbation theory the reality of the perturbed eigenvalues of a class of PT-symmetric Hamiltonians is proved using stability techniques. We apply this method to PT-symmetric unperturbed Hamiltonians perturbed by PT-symmetric additional interactions.
Sun, 01 Jan 2006 00:00:00 GMThttp://hdl.handle.net/11585/371452006-01-01T00:00:00ZClassical limit of the quantum
Zeno effecthttp://hdl.handle.net/11585/87153Titolo: Classical limit of the quantum
Zeno effect
Abstract: 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 not evolve. This effect is at variance with the classical evolution, which obviously is not affected by any observations. By a semiclassical analysis we will show that the quantum Zeno effect vanishes at all orders, when the Planck constant tends to zero, and thus it is a purely quantum phenomenon without classical analog, at the same level of tunneling.
Fri, 01 Jan 2010 00:00:00 GMThttp://hdl.handle.net/11585/871532010-01-01T00:00:00ZPT symmetric non-selfadjoint
operators, diagonalizable and non-diagonalizable, with real discrete spectrumhttp://hdl.handle.net/11585/53958Titolo: PT symmetric non-selfadjoint
operators, diagonalizable and non-diagonalizable, with real discrete spectrum
Abstract: Consider the operator family
H(g):=H_0+igW.
H_0 is the quantum harmonic
oscillator with rational frequencies , W a P symmetric bounded potential, and g a real coupling
constant.
We show that if |g|< does not exceed an explicitly determined constant, the spectrum of H(g) is
real and discrete. Moreover we show that the ope-rator
H(g)=a*_1 a_1+a*_2a_2+ig a*_2a_1 has real discrete spectrum but is not diagonalizable.
Mon, 01 Jan 2007 00:00:00 GMThttp://hdl.handle.net/11585/539582007-01-01T00:00:00ZQuadratic PT -symmetric operators with real spectrum and similarity to self-adjoint operatorshttp://hdl.handle.net/11585/132841Titolo: Quadratic PT -symmetric operators with real spectrum and similarity to self-adjoint operators
Abstract: 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.
Sun, 01 Jan 2012 00:00:00 GMThttp://hdl.handle.net/11585/1328412012-01-01T00:00:00Z7th Bologna workshop on Conformal Field Theory and Integrable Modelshttp://hdl.handle.net/11585/36005Titolo: 7th Bologna workshop on Conformal Field Theory and Integrable Models
Abstract: Following a tradition started in 1993, the 6th Bologna Workshop on CFT AND INTEGRABLE MODELS, held at the Department of Physics of Bologna University (Italy), on July 3-8, 2006 (inclusive), is an International Workshop organized by the Bologna Theory Group under the auspices of the University and with sponsorization of INFN.
It is intended to promote the exchange of ideas at an advanced technical level among researchers working in this rapidly evolving field., with particular attention to the applications to Quantum Field Theory, Statistical Mechanics and Condensed Matter Physics.
Besides a series of plenary talks (of approx. 1h.), there has been room for a number of short communications of 30 min. and a poster session.
The workshop has been organized jointly with the "5th International Workshop on Pseudo-Hermitian Hamiltonians in Quantum Physics" to promote the exchange of ideas between mathematicians and theoretical physicists on this subjects having many points in common.
The topics covered by the workshop are:
* Bulk and Boundary Conformal Field Theory
* Integrable Boundaries and Defects
* Bethe Ansatz techniques and Finite Size Effects
* Links of Integrability, Quantum Mechanics and Ordinary Differential Equations
* Applications to Condensed Matter and Statisitical Mechanics
* SLE and applications of CFT to non-equilibrium phenomena
* Integrability in (Super-)Yang-Mills Field Theories
The list of plenary invited speakers is the following:
* Carl Bender (Washington Univ, St. Louis - USA)
* Michael Berry (Bristol - UK)
* Massimo Bianchi (Roma II - Italy)
* Andrea Cappelli (INFN Firenze - Italy)
* Sebastian Eggert (Kaiserlautern - Germany)
* Petr Kulish (Skt. Petersburg - Russia)
* Lev Lipatov (Skt. Petersburg - Russia)
* Alexander Manashov (Regensburg - Germany)
* Barry McCoy (Stony Brook - USA)
* Arianna Montorsi (Politecnico di Torino - Italy)
* Paul Pearce (Melbourne - Australia)
* Junji Suzuki (Shizuoka - Japan)
More details on the program and talks can be obtained at the Web Page http://www-th.bo.infn.it/conferences/cft06
Sun, 01 Jan 2006 00:00:00 GMThttp://hdl.handle.net/11585/360052006-01-01T00:00:00ZOn a class of non selfadjoint quantum non-linear oscillators with real spectrumhttp://hdl.handle.net/11585/9343Titolo: On a class of non selfadjoint quantum non-linear oscillators with real spectrum
Sat, 01 Jan 2005 00:00:00 GMThttp://hdl.handle.net/11585/93432005-01-01T00:00:00ZLocalization in infinite billiards: a comparison between quantum and classical ergodicityhttp://hdl.handle.net/11585/1607Titolo: Localization in infinite billiards: a comparison between quantum and classical ergodicity
Thu, 01 Jan 2004 00:00:00 GMThttp://hdl.handle.net/11585/16072004-01-01T00:00:00ZCanonical Expansion of PT-Symmetric Operators and Perturbation Theoryhttp://hdl.handle.net/11585/1610Titolo: Canonical Expansion of PT-Symmetric Operators and Perturbation Theory
Thu, 01 Jan 2004 00:00:00 GMThttp://hdl.handle.net/11585/16102004-01-01T00:00:00ZConvergence of a quantum normal form and an exact quantization formulahttp://hdl.handle.net/11585/113090Titolo: Convergence of a quantum normal form and an exact quantization formula
Abstract: The operator
$-i\hbar\omega\cdot\nabla$ on $L^2(\T^l)$, quantizing the linear flow of diophantine
frequencies $\om=(\om_1,\ldots,\om_l)$ over $\T^l$, $l>1$, is
perturbed by the quantization of a function $\V_\om(\xi,x)=\V(\om\cdot \xi,x): \R^l\times\T^l\to\R$,
$z\mapsto \V(z,x): \R\times\T^l \to\R$ real-holomorphic.
The corresponding quantum normal form (QNF) is proved to converge uniformly in $\hbar\in [0,1]$. This yields non-trivial examples of quantum integrable systems, an exact
quantization formula for the spectrum,
and a convergence criterion for the Birkhoff normal form, valid
for perturbations holomorphic away from the origin. The main technical aspect
concerns the quantum homological equation. Its solution is
constructed,
and uniformly estimated, by solving
the Moyal equation for the operator symbols.
The KAM iteration can thus be implemented on the symbols,
and its uniform convergence proved, for $|\ep|<\ep^\ast$; $\ep^\ast>0$ is estimated in terms only of the diophantine constants of $\om$. This entails the QNF convergence.
Sun, 01 Jan 2012 00:00:00 GMThttp://hdl.handle.net/11585/1130902012-01-01T00:00:00Z