78 research outputs found
Universality, the QCD critical/tricritical point and the quark number susceptibility
The quark number susceptibility near the QCD critical end-point (CEP), the
tricritical point (TCP) and the O(4) critical line at finite temperature and
quark chemical potential is investigated. Based on the universality argument
and numerical model calculations we propose a possibility that the hidden
tricritical point strongly affects the critical phenomena around the critical
end-point. We made a semi-quantitative study of the quark number susceptibility
near CEP/TCP for several quark masses on the basis of the
Cornwall-Jackiw-Tomboulis (CJT) potential for QCD in the improved-ladder
approximation. The results show that the susceptibility is enhanced in a wide
region around CEP inside which the critical exponent gradually changes from
that of CEP to that of TCP, indicating a crossover of different universality
classes.Comment: 18 pages, 10 figure
Numerical Portrait of a Relativistic Thin Film BCS Superfluid
We present results of numerical simulations of the 2+1d Nambu - Jona-Lasinio
model with a non-zero baryon chemical potential mu including the effects of a
diquark source term. Diquark condensates, susceptibilities and masses are
measured as functions of source strength j. The results suggest that diquark
condensation does not take place in the high density phase mu>mu_c, but rather
that the condensate scales non-analytically with j implying a line of critical
points and long range phase coherence. Analogies are drawn with the low
temperature phase of the 2d XY model. The spectrum of the spin-1/2 sector is
also studied yielding the quasiparticle dispersion relation. There is no
evidence for a non-zero gap; rather the results are characteristic of a normal
Fermi liquid with Fermi velocity less than that of light. We conclude that the
high density phase of the model describes a relativistic gapless thin film BCS
superfluid.Comment: 37 pages, 16 figure
Variación genética en el complejo infraespecífico de chayote evaluada mediante sistemas isoenzimáticos
Entropy Stable Finite Volume Approximations for Ideal Magnetohydrodynamics
This article serves as a summary outlining the mathematical entropy analysis of the ideal magnetohydrodynamic (MHD) equations. We select the ideal MHD equations as they are particularly useful for mathematically modeling a wide variety of magnetized fluids. In order to be self-contained we first motivate the physical properties of a magnetic fluid and how it should behave under the laws of thermodynamics. Next, we introduce a mathematical model built from hyperbolic partial differential equations (PDEs) that translate physical laws into mathematical equations. After an overview of the continuous analysis, we thoroughly describe the derivation of a numerical approximation of the ideal MHD system that remains consistent to the continuous thermodynamic principles. The derivation of the method and the theorems contained within serve as the bulk of the review article. We demonstrate that the derived numerical approximation retains the correct entropic properties of the continuous model and show its applicability to a variety of standard numerical test cases for MHD schemes. We close with our conclusions and a brief discussion on future work in the area of entropy consistent numerical methods and the modeling of plasmas
Isozymic discrimination of tropical Australian populations of mesquite (Prosopis spp.): implications for biological control
Genetic Variation in the Endangered Santa Ana River Woolly-Star, Eriastrum densifolium ssp. sanctorum (Polemoniaceae)
Enzyme Electrophoretic Evidence for Diploidy in Japanese Woodwardia japonica (L.f.) Sm. (Blechnaceae, Pteridophyte) with 2n = 68
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