Person:
Fernández Pérez, Luis Antonio

First Name

Luis Antonio

Last Name

Fernández Pérez

URI

https://hdl.handle.net/20.500.14352/75087

Affiliation

Universidad Complutense de Madrid

Faculty / Institute

Ciencias Físicas

Department

Física Teórica

Area

Física Teórica

Identifiers

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Now showing 1 - 10 of 27

Finite size effects on measures of critical exponents in d=3 O(N) models
(Physics letters B, 1996) Ballesteros, H. G.; Fernández Pérez, Luis Antonio; Martín Mayor, Víctor; Muñoz Sudupe, Antonio
We study the critical properties of three-dimensional O(N) models, for N = 2,3,4. Parameterizing the leading correctionsto-scaling for the r] exponent, we obtain a reliable infinite volume extrapolation, incompatible with previous Monte Carlo values, but in agreement with e-expansions. We also measure the critical exponent related with the tensorial magnetization as well as the v exponents and critical couplings.
Antiferromagnetic O(N) models in four dimensions
(Physics letters B, 1998) Ballesteros, H. G.; Carmona, J. M.; Fernández Pérez, Luis Antonio; Tarancón, A.
We study the antiferromagnetic O(N). N model in the F_(4) lattice. Monte Carlo simulations are applied for investigating the behavior of the transition for N = 2,3. The numerical results show a first order nature but with a large correlation length. The N = ∞ limit is also considered with analytical methods.
Study of the Coulomb-Higgs transition in the abelian Higgs model
(Physics letters B, 1998) Cruz, A.; Íñiguez, D.; Fernández Pérez, Luis Antonio; Muñoz Sudupe, Antonio; Tarancón, A.
The order of the Coulomb-Higgs transition in the U (1) -Higgs model with unfrozen modulus of the scalar field is studied. Large lattices (up to 24^4 in one case) and high statistics are used. We fix β = 1.15 and explore specially a region of λ-values where metastability is observed. We study the thermodynamical limit of several observables, in particular, the latent heat, the specific heat, the decrement of the free energy between the maxima and the central minimum of the two-peaked histogram, the Binder cumulant and the displacement of the critical coupling with the lattice size. The results point towards a second order transition for λ ≥ 0.005, while for smaller values of λ the strong metastability growing with the lattice size seems to derive from a first order character.
New universality class in three dimensions? The antiferromagnetic RP^(2) model
(Physics letters B, 1996) Ballesteros, H. G.; Fernández Pérez, Luis Antonio; Martín Mayor, Víctor; Muñoz Sudupe, Antonio
We present the results of a Monte Carlo simulation of the RP^(2) model in three dimensions with negative coupling. We observe a second order phase transition between the disordered phase and an antiferromagnetic, unfrustrated, ordered one. We measure, with a finite size scaling analysis, the thermal exponent, obtaining v = 0.784(g). We have found two magnetic-type relevant operators whose related YJ exponents are 0.038( 2) and 1.338( 8) respectively.
The Coulomb-Higgs transition of the three-parameter U(1)-Higgs model
(Nuclear Physics B-Proceedings Supplements, 1995) Cruz, A.; Íñiguez, D.; Tarancón, A.; Fernández Pérez, Luis Antonio; Muñoz Sudupe, Antonio
We find a first order Coulomb-Higgs phase transition at moderately large values of the coupling λ, and no evidence for a change of order at any finite value of it.
Instanton-like contributions to the dynamics of Yang-Mills fields on the twisted torus
(1993) García Pérez, M.; González Arroyo, A.; Martínez, P.; Fernández Pérez, Luis Antonio; Muñoz Sudupe, Antonio; Ruiz Lorenzo, J. J.; Azcoiti, V.; Campos, I.; Ciria, J.C.; Cruz, A.; Íñiguez, D.; Lesmes, F.; Badoni, D.; Pech, J.
We study SU(2) lattice gauge theory in small volumes and with twist m ⃗ = (1, 1, 1). We investigate the presence of the periodic instantons of Q = 1/2 and determine their free energy and their contribution to the splitting of energy flux sectors E(e ⃗ = (1, 1, 1)) − E(e ⃗ = (0, 0, 0)).
Monte Carlo study of O(3) antiferromagnetic models in three dimensions
(Physical review B, 1996) Ballesteros, H. G.; Fernández Pérez, Luis Antonio; Martín Mayor, Víctor; Muñoz Sudupe, Antonio
We study three antiferromagnetic formulations of the O(3) spin model in three dimensions by means of Monte Carlo simulations: (1) a two parameter s model with nearest- and next-nearest neighbors couplings in a cubic lattice; (2) a face-centered-cubic lattice with nearest-neighbor interaction; (3) a cubic lattice with a set of fully frustrating couplings. We discuss in all cases the vacua properties and analyze the phase transitions. Using finite-size scaling analysis we conclude that all phase transitions found are of first order.
Scaling corrections: site percolation and Ising model in three dimensions
(Journal of Physics A-Mathematical and General, 1999) Ballesteros, H.G.; Fernández Pérez, Luis Antonio; Martín Mayor, Víctor; Muñoz Sudupe, Antonio; Parisi, G.; Ruiz Lorenzo, J. J.
Using Finite-Size Scaling techniques we obtain accurate results for critical quantities of the Ising model and the site percolation, in three dimensions. We pay special attention in parameterizing the corrections-to-scaling, what is necessary to put the systematic errors below the statistical ones.
Phase diagram of d=4 Ising model with two couplings
(Physics letters B, 1996) Alonso, J. L.; Carmona, J. M.; Clemente Gallardo, J.; Fernández Pérez, Luis Antonio; Íñiguez, D.; Tarancón, A.; Ullod, C. L.
We study the phase diagram of the four dimensional king model with first and second neighbour couplings, especially in the antiferromagnetic region, by using Mean Field and Monte Carlo methods. From the latter, all the transition lines seem to be first order except that between ferromagnetic and disordered phases in a region including the first-neighbour Ising transition point.
Is the antiferromagnetic RP^(2) model in four dimensions trivial?
(Physical review D, 1997) Ballesteros, H. G.; Carmona, J. M.; Fernández Pérez, Luis Antonio; Martín Mayor, Víctor; Muñoz Sudupe, Antonio; Tarancón, A.
We study the antiferromagnetic RP^(2) model in four dimensions. We find a second order transition with two order parameters, one ferromagnetic and the other antiferromagnetic. The antiferromagnetic sector has mean- field critical exponents and a renormalized coupling which goes to zero in the continuum limit. The exponents of the ferromagnetic channel are not the mean-field ones, but the difference can be interpreted as logarithmic corrections. We perform a detailed analysis of these corrections and conclude the triviality of the continuum limit of this model.