148,664 research outputs found
The CMB - Contemporary Measurements and Cosmology
Since the discovery of the Cosmic Microwave Background (CMB) in 1965,
characterization of the CMB anisotropy angular power spectrum has become
somewhat of a holy grail for experimental cosmology. Because CMB anisotropy
measurements are difficult, the full potential of the CMB is only now being
realized. Improvements in experimental techniques and detector technology have
yielded an explosion of progress in the past couple of years resulting in the
ability to use measurements of the CMB to place meaningful constraints on
cosmological parameters. In this review, I discuss the theory behind the CMB
but focus primarily on the experiments, reviewing briefly the history of CMB
anisotropy measurements and focusing on the recent experiments that have
revolutionized this field. Results from these modern experiments are reviewed
and the cosmological implications discussed. I conclude with brief comments
about the future of CMB physics.Comment: 18 pages including 5 ps figures. GR16 proceedings to appear in World
Scientifi
The influence of strange quarks on QCD phase diagram and chemical freeze-out: Results from the hadron resonance gas model
We confront the lattice results on QCD phase diagram for two and three
flavors with the hadron resonance gas model. Taking into account the
truncations in the Taylor-expansion of energy density done on the
lattice at finite chemical potential , we find that the hadron resonance
gas model under the condition of constant describes very well the
lattice phase diagram. We also calculate the chemical freeze-out curve
according to the entropy density . The -values are taken from lattice QCD
simulations with two and three flavors. We find that this condition is
excellent in reproducing the experimentally estimated parameters of the
chemical freeze-out.Comment: 5 pages, 3 figures and 1 table Talk given at VIIIth international
conference on ''Strangeness in Quark Matter'' (SQM 2004), Cape Town, South
Africa, Sep. 15-20 200
Conditions driving chemical freeze-out
We propose the entropy density as the thermodynamic condition driving best
the chemical freeze-out in heavy-ion collisions. Taking its value from lattice
calculations at zero chemical potential, we find that it is excellent in
reproducing the experimentally estimated freeze-out parameters. The two
characteristic endpoints in the freeze-out diagram are reproduced as well.Comment: 8 pages, 5 eps figure
Entropy for Color Superconductivity in Quark Matter
We study a model for color superconductivity with both three colors and
massless flavors including quark pairing. By using the Hamiltonian in the
color-flavor basis we can calculate the quantum entropy. From this we are able
to further investigate the phases of the color superconductor, for which we
find a rather sharp transition to color superconductivity above a chemical
potential around MeV.Comment: 10 pages, 2 eps-figure
Supersymmetric SO(10) Grand Unification at the LHC and Beyond
We study models of supersymmetric grand unification based on the SO(10) gauge
group. We investigate scenarios of non-universal gaugino masses including
models containing a mixture of two representations of hidden sector chiral
superfields. We analyse the effect of excluding mu from the fine-tuning
measure, and confront the results with low energy constraints, including the
Higgs boson mass, dark matter relic density and supersymmetry bounds. We also
determine high scale Yukawa coupling ratios and confront the results with
theoretical predictions. Finally, we present two additional benchmarks that
should be explored at the LHC and future colliders.Comment: Published versio
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