SM&FT 2022 - The XIX Workshop on Statistical Mechanics and nonpertubative Field Theory

Session

Session 3 B

19 Dec 2022, 15:00

aula B

Conveners

Session 3 B

• Andrea Puglisi (CNR-ISC and Sapienza Roma)

96. Localization, negative temperatures and ensemble inequivalence in the discrete nonlinear Schrodinger equation: a large deviations approach.

Prof. Giacomo Gradenigo (GSSI)

19/12/2022, 15:00

We present a detailed account of a first-order localization transition in the discrete nonlinear Schrödinger equation, where the localized phase is associated with the high energy region in parameter space [1,2]. We show that, due to ensemble inequivalence, this phase is thermodynamically stable only in the microcanonical ensemble. In particular, we obtain an explicit expression of the...

82. Microscopic theory for the diffusion of an active particle in a crowded environment

Alessandro Sarracino (Dipartimento di Ingegneria, Università della Campania "L. Vanvitelli")

19/12/2022, 15:25

We study the diffusion coefficient of an active tracer in a schematic crowded environment, represented as a lattice gas of passive particles with hardcore interactions. Starting from the Master Equation of the problem, we put forward a closure approximation that goes beyond trivial mean field and provides the diffusion coefficient for arbitrary density. The approximation is accurate for a wide...

95. Ordering kinetics with long-range interactions

Federico Corberi (SA)

19/12/2022, 15:45

We discuss the phenomenon of phase-ordering after a temperature quench in systems with long-range interactions decaying with distance $r$ as $r^{-\alpha}$, focusing mainly on the Ising model in $d=1$.
For $\alpha >d$ one observes formation and growth of ordered domains, with scaling exponents continuously depending on
$\alpha$. For $\alpha=0$ one has mean field, where the system...

63. Active semiflexible polymer under shear flow

Antonio Lamura (IAC CNR)

19/12/2022, 16:05

The dynamic behavior of a self-propelled semiflexible filament of length L is con-
sidered under the action of a linear shear flow. The system is studied by using
Brownian multi-particle collision dynamics. The system can be characterized in
terms of the persistence length Lp of the chain, of the Peclet number, and of
the Weissenberg number. The quantity Lp/L measures the bending rigidity...

91. A predictive model for the thermomechanical melting transition of double stranded DNA

Dr Giuseppe Florio (BA)

19/12/2022, 16:25

By extending the classical Peyrard-Bishop model, we are able to obtain a fully analytical description for the mechanical response of DNA under stretching at variable values of temperature, number of base pairs and intrachains and interchains bonds stiffness. In order to compare elasticity and temperature effects, we first analyze the system in the zero temperature mechanical limit, important...

110. Towards learning a Lattice Boltzmann collisional operator

Alessandro Gabbana

19/12/2022, 16:45

In this work we explore the possibility of learning a collisional operator
for the Lattice Boltzmann Method from data using a deep learning approach.
We present results where a Neural Network is successfully trained as a surrogate of the single relaxation time BGK operator.
We show that only by embedding in the Neural Network physical properties such as
conservation laws and symmetries,...