1,837 research outputs found
Phase transition of the nucleon-antinucleon plasma at different ratios
We investigate phase transitions for the Walecka model at very high
temperatures. As is well known, depending on the parametrization of this model
and for the particular case of a zero chemical potential (), a first
order phase transition is possible \cite{theis}. We investigate this model for
the case in which . It turns out that, in this situation, phases
with different values of antinucleon-nucleon ratios and net baryon densities
may coexist. We present the temperature versus antinucleon-nucleon ratio as
well as the temperature versus the net baryon density for the coexistence
region. The temperature versus chemical potential phase diagram is also
presented.Comment: 5 pages, 8 figure
Finite temperature results on the 2d Ising model with mixed perturbation
A numerical study of finite temperature features of thermodynamical
observables is performed for the lattice 2d Ising model. Our results support
the conjecture that the Finite Size Scaling analysis employed in the study of
integrable perturbation of Conformal Field Theory is still valid in the present
case, where a non-integrable perturbation is considered.Comment: 9 pages, Latex, added references and improved introductio
Form factors in finite volume I: form factor bootstrap and truncated conformal space
We describe the volume dependence of matrix elements of local fields to all
orders in inverse powers of the volume (i.e. only neglecting contributions that
decay exponentially with volume). Using the scaling Lee-Yang model and the
Ising model in a magnetic field as testing ground, we compare them to matrix
elements extracted in finite volume using truncated conformal space approach to
exact form factors obtained using the bootstrap method. We obtain solid
confirmation for the form factor bootstrap, which is different from all
previously available tests in that it is a non-perturbative and direct
comparison of exact form factors to multi-particle matrix elements of local
operators, computed from the Hamiltonian formulation of the quantum field
theory. We also demonstrate that combining form factor bootstrap and truncated
conformal space is an effective method for evaluating finite volume form
factors in integrable field theories over the whole range in volume.Comment: 43 pages, 31 eps figures, LaTeX2e file. v2: main theoretical argument
substantially expanded and clarified, typos and references correcte
Form factors in the Bullough-Dodd related models: The Ising model in a magnetic field
We consider particular modification of the free-field representation of the
form factors in the Bullough-Dodd model. The two-particles minimal form factors
are excluded from the construction. As a consequence, we obtain convenient
representation for the multi-particle form factors, establish recurrence
relations between them and study their properties. The proposed construction is
used to obtain the free-field representation of the lightest particles form
factors in the perturbed minimal models. As a significant example
we consider the Ising model in a magnetic field. We check that the results
obtained in the framework of the proposed free-field representation are in
agreement with the corresponding results obtained by solving the bootstrap
equations.Comment: 20 pages; v2: some misprints, textual inaccuracies and references
corrected; some references and remarks adde
Structure of interfaces at phase coexistence. Theory and numerics
We compare results of the exact field theory of phase separation in two dimensions with Monte Carlo simulations for the q-state Potts model with boundary conditions producing an interfacial region separating two pure phases. We confirm in particular the theoretical predictions that below critical temperature the surplus of non-boundary colors appears in drops along a single interface, while for q > 4 at critical temperature there is formation of two interfaces enclosing a macroscopic disordered layer. These qualitatively different structures of the interfacial region can be discriminated through a measurement at a single point for different system sizes
Postcard: Polita and Berge, European Sensational Dancers
This black and white printed postcard features three photographs with decorative linework around them. The photo on the left depicts a man standing with a woman lifted and standing on his shoulder. The photo in the middle depicts a woman standing with her arms in the air and she looks off camera. The picture on the right depicts a woman in a man\u27s embrace and her hand touches his jawline. Printed text is at the bottom of the card. Handwriting is on the back of the card.https://scholars.fhsu.edu/tj_postcards/2329/thumbnail.jp
Universal Ratios in the 2-D Tricritical Ising Model
We consider the universality class of the two-dimensional Tricritical Ising
Model. The scaling form of the free-energy naturally leads to the definition of
universal ratios of critical amplitudes which may have experimental relevance.
We compute these universal ratios by a combined use of results coming from
Perturbed Conformal Field Theory, Integrable Quantum Field Theory and numerical
methods.Comment: 4 pages, LATEX fil
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