Zobrazeno 1 - 10
of 80
pro vyhledávání: '"Ostilli, Massimo"'
Autor:
Ostilli, Massimo, Presilla, Carlo
Publikováno v:
J. Phys. A: Math. Theor. 55, 505004 (2022)
We formalize and prove the extension to finite temperature of a class of quantum phase transitions, acting as condensations in the space of states, recently introduced and discussed at zero temperature~(Ostilli and Presilla 2021 \textit{J. Phys. A: M
Externí odkaz:
http://arxiv.org/abs/2209.13244
Autor:
Ostilli, Massimo, Presilla, Carlo
Publikováno v:
Phys. Rev. A 108, 022205 (2023)
In nature, everything occurs at finite temperature and quantum phase transitions (QPTs) cannot be an exception. Nevertheless, they are still mainly discussed and formulated at zero temperature. We show that the condensation QPTs recently introduced a
Externí odkaz:
http://arxiv.org/abs/2203.05803
Publikováno v:
Phys. Rev. A 104, 023309 (2021)
When noninteracting fermions are confined in a $D$-dimensional region of volume $\mathrm{O}(L^D)$ and subjected to a continuous (or piecewise continuous) potential $V$ which decays sufficiently fast with distance, in the thermodynamic limit, the grou
Externí odkaz:
http://arxiv.org/abs/2104.05492
Autor:
Ostilli, Massimo, Presilla, Carlo
Publikováno v:
Phys. Rev. Lett. 127, 040601 (2021)
We study the ground state of a system of spinless electrons interacting through a screened Coulomb potential in a lattice ring. By using analytical arguments, we show that, when the effective interaction compares with the kinetic energy, the system f
Externí odkaz:
http://arxiv.org/abs/1912.11357
Autor:
Ostilli, Massimo
Publikováno v:
Phys. Rev. E 102, 052126 (2020)
The small-world effect is a universal feature used to explain many different phenomena like percolation, diffusion, and consensus. Starting from any regular lattice of $N$ sites, the small-world effect can be attained by rewiring randomly an $\mathca
Externí odkaz:
http://arxiv.org/abs/1912.01406
Autor:
Nicolao, Lucas, Ostilli, Massimo
Publikováno v:
Physica A 533, 121920 (2019)
In recent years, Twitter data related to political trends have tentatively been used to make predictions (poll) about several electoral events. Given $q$ candidates for an election and a time-series of Twitts (short messages), one can extract the $q$
Externí odkaz:
http://arxiv.org/abs/1901.10984
Autor:
Ostilli, Massimo, Presilla, Carlo
Publikováno v:
J. Phys. A: Math. Theor. 54, 055005 (2021)
We demonstrate that a large class of first-order quantum phase transitions, namely, transitions in which the ground state energy per particle is continuous but its first order derivative has a jump discontinuity, can be described as a condensation in
Externí odkaz:
http://arxiv.org/abs/1712.05294
Publikováno v:
Phys. Rev. A 95, 042107 (2017)
In a recent work, we have derived simple Lindblad-based equations for the thermalization of systems in contact with a thermal reservoir. Here, we apply these equations to the Lipkin-Meshkov-Glick model (LMG) in contact with a blackbody radiation and
Externí odkaz:
http://arxiv.org/abs/1611.06720
Autor:
Ostilli, Massimo, Presilla, Carlo
Publikováno v:
Phys. Rev. A 95, 062112 (2017)
We study the thermalization of an ensemble of $N$ elementary, arbitrarily-complex, quantum systems, mutually noninteracting but coupled as electric or magnetic dipoles to a blackbody radiation. The elementary systems can be all the same or belong to
Externí odkaz:
http://arxiv.org/abs/1611.03127
Autor:
Ostilli, Massimo, Presilla, Carlo
Publikováno v:
Phys. Rev. A 94, 032514 (2016)
We review the calculation of Fermi's golden rule for a system of $N$-body dipoles, magnetic or electric, weakly interacting with a blackbody radiation. By using the magnetic or electric field-field correlation function evaluated in the 1960s for the
Externí odkaz:
http://arxiv.org/abs/1606.08276