3,697 research outputs found
Generalized CMB initial conditions with pre-equality magnetic fields
The most general initial conditions of CMB anisotropies, compatible with the
presence of pre-equality magnetic fields, are derived. When the plasma is
composed by photons, baryons, electrons, CDM particles and neutrinos, the
initial data of the truncated Einstein-Boltzmann hierarchy contemplate one
magnetized adiabatic mode and four (magnetized) non-adiabatic modes. After
obtaining the analytical form of the various solutions, the Einstein-Boltzmann
hierarchy is numerically integrated for the corresponding sets of initial data.
The TT, TE and EE angular power spectra are illustrated and discussed for the
magnetized generalization of the CDM-radiation mode, of the baryon-radiation
mode and of the non-adiabatic mode of the neutrino sector. Mixtures of initial
conditions are examined by requiring that the magnetized adiabatic mode
dominates over the remaining non-adiabatic contributions. In the latter case,
possible degeneracies between complementary sets of initial data might be
avoided through the combined analysis of the TT, TE and EE angular power
spectra at high multipoles (i.e. ).Comment: 28 pages, 24 included figures in eps styl
VLBI observations of nearby radio loud Active Galactic Nuclei
We present an update of the parsec scale properties of the Bologna Complete
Sample consisting of 95 radio sources from the B2 Catalog of Radio Sources and
the Third Cambridge Revised Catalog (3CR), with z < 0.1. Thanks to recent new
data we have now parsec scale images for 76 sources of the sample. Most of them
show a one-sided jet structure but we find a higher fraction of two-sided
sources in comparison with previous flux-limited VLBI surveys. A few peculiar
sources are presented and discussed in more detail.Comment: 6 pages, 7 figures, Proceedings for "The Universe under the
Microscope" (AHAR 2008), April 2008, to be published in Journal of Physics:
Conference Series by Institute of Physics Publishing; R. Schoedel, A. Eckart,
S. Pfalzner, and E. Ros ed
Clan structure analysis and new physics signals in pp collisions at LHC
The study of possible new physics signals in global event properties in pp
collisions in full phase space and in rapidity intervals accessible at LHC is
presented. The main characteristic is the presence of an elbow structure in
final charged particle MD's in addition to the shoulder observed at lower c.m.
energies.Comment: 9 pages, talk given at Focus on Multiplicity (Bari, Italy, June 2004
Scenarios for multiplicity distributions in pp collisions in the TeV energy region
Possible scenarios based on available experimental data and phenomenological
knowledge of the GeV energy region are extended to the TeV energy region in the
framework of the weighted superposition mechanism of soft and semi-hard events.
KNO scaling violations, forward-backward multiplicity correlations, Hq vs. q
oscillations and shoulder structures are discussed.Comment: 10 pages, 10 figures, talk given at "Focus on Multiplicity" (Bari,
Italy, June 2004
Maps of zeroes of the grand canonical partition function in a statistical model of high energy collisions
Theorems on zeroes of the truncated generating function in the complex plane
are reviewed. When examined in the framework of a statistical model of high
energy collisions based on the negative binomial (Pascal) multiplicity
distribution, these results lead to maps of zeroes of the grand canonical
partition function which allow to interpret in a novel way different classes of
events in pp collisions at LHC c.m. energies.Comment: 17 pages, figures (ps included); added references, some figures
enlarged. To appear in J. Phys.
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