19,221 research outputs found
BEC-BCS crossover in a cold and magnetized two color NJL model
The BEC-BCS crossover for a NJL model with diquark interactions is studied in
the presence of an external magnetic field. Particular attention is paid to
different regularization schemes used in the literature. A thorough comparison
of results is performed for the case of a cold and magnetized two-color NJL
model. According to our results, the critical chemical potential for the BEC
transition exhibits a clear inverse magnetic catalysis effect for magnetic
fields in the range . As for the BEC-BCS
crossover, the corresponding critical chemical potential is very weakly
sensitive to magnetic fields up to , showing a much smaller
inverse magnetic catalysis as compared to the BEC transition, and displays a
strong magnetic catalysis from this point on.Comment: 15 pages, 8 figures; v2 PRD versio
How much dark matter is there inside early-type galaxies?
We study the luminous mass as a function of the dynamical mass inside the
effective radius (r_e) of early-type galaxies (ETGs) to search for differences
between these masses. We assume Newtonian dynamics and that any difference
between these masses is due to the presence of dark matter. We use several
samples of ETGs -ranging from 19 000 to 98 000 objects- from the ninth data
release of the Sloan Digital Sky Survey. We perform Monte Carlo (MC)
simulations of galaxy samples and compare them with real samples. The main
results are: i) MC simulations show that the distribution of the dynamical vs.
luminous mass depends on the mass range where the ETGs are distributed
(geometric effect). This dependence is caused by selection effects and
intrinsic properties of the ETGs. ii) The amount of dark matter inside r_e is
approximately 7% +- 22%. iii) This amount of dark matter is lower than the
minimum estimate (10%) found in the literature and four times lower than the
average (30%) of literature estimates. However, if we consider the associated
error, our estimate is of the order of the literature average.Comment: 24 pages, 12 figures. MNRAS accepte
Indução de resposta imune contra novas proteínas de membrana de Anaplasma marginale em Camundongos BALB/c.
bitstream/CNPGC-2010/13221/1/COT116.pd
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