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. $\ell >1000$).Comment: 28 pages, 24 included figures in eps styl

Cosmic rays measurements around the knee of the primary spectrum

In this contribution I will summarize and discuss some recent results about the study of the knee of the cosmic rays energy spectrum, indicating that this spectral feature is originated by astrophysical processes. I will then discuss the current experimental efforts that are giving further insights. Latest all particle spectrum measurements have shown that, between 1016eV and 1018eV, the spectrum cannot be described by a single slope power law: an hardening around 1016eV and a steepeningaround 1017eV have been observed. This last feature has been attributed, by the KASCADE-Grande experiment, to the heavy primary component, confirming that the energy of the elemental spectra change of slope increase with the mass of the primary particle

Ultra-Transparent Antarctic Ice as a Supernova Detector

We have simulated the response of a high energy neutrino telescope in deep Antarctic ice to the stream of low energy neutrinos produced by a supernova. The passage of a large flux of MeV-energy neutrinos during a period of seconds will be detected as an excess of single counting rates in all individual optical modules. We update here a previous estimate of the performance of such an instrument taking into account the recent discovery of absorption lengths of several hundred meters for near-UV photons in natural deep ice. The existing AMANDA detector can, even by the most conservative estimates, act as a galactic supernova watch.Comment: 9 pages, Revtex file, no figures. Postscript file also available from http://phenom.physics.wisc.edu/pub/preprints/1995/madph-95-888.ps.Z or from ftp://phenom.physics.wisc.edu/pub/preprints/1995/madph-95-888.ps.

Study of the effect of neutrino oscillation on the supernova neutrino signal with the LVD detector

We present an update of our previous study (astro-ph/0112312) on how $\nu$ oscillations affect the signal from a supernova core collapse observed in the LVD detector at LNGS. In this paper we use a recent, more precise determination of the cross section (astro-ph/0302055) to calculate the expected number of inverse beta decay events, we introduce in the simulation also the $\nu$-{\rm Fe} interactions, we include the Earth matter effects and, finally, we study also the inverted mass hierarchy case.Comment: 4 pages, 4 figures, to appear in the Proceedings of ICRC 200

Predicting Proton-Air Cross Sections at sqrt s ~30 TeV, using Accelerator and Cosmic Ray Data

We use the high energy predictions of a QCD-inspired parameterization of all accelerator data on forward proton-proton and antiproton-proton scattering amplitudes, along with Glauber theory, to predict proton-air cross sections at energies near \sqrt s \approx 30 TeV. The parameterization of the proton-proton cross section incorporates analyticity and unitarity, and demands that the asymptotic proton is a black disk of soft partons. By comparing with the p-air cosmic ray measurements, our analysis results in a constraint on the inclusive particle production cross section.Comment: 9 pages, Revtex, uses epsfig.sty, 5 postscript figures. Minor text revisions. Systematic errors in k included, procedure for extracting k clarified. Previously undefined symbols now define