Cooper pairing with finite angular momentum: BCS versus Bose limits

We revisit the old problem of exotic superconductivity as Cooper pairing with finite angular momentum emerging from a central potential. Based on some general considerations, we suggest that the phenomenon is associated with interactions that keep electrons at some particular, finite distance r(0), and occurs at a range of intermediate densities n similar to 1/r(0)(3). We discuss the ground state and the critical temperature in the framework of a standard functional-integral theory of the BCS to Bose crossover. We find that, due to the lower energy of two-body bound states with l = 0, the rotational symmetry of the ground state is always restored on approaching the Bose limit. Moreover in that limit the critical temperature is always higher for pairs with l = 0. The breaking of the rotational symmetry of the continuum by the superfluid state thus seems to be a property of weakly-attractive, non-monotonic interaction potentials, at intermediate densities

Analysis of the BATSE Continuous MER data

The CGRO/BATSE database includes many types of data such as the 16-channel continuous background or medium energy resolution burst data (CONT and MER data types). We have calculated some four hundred burst's medium energy resolution spectra and Principal Component Analysis has been applied. We found five components can describe GRBs' spectra.Comment: 4 pages, 2 figures, accepted in Nuovo Ciment

Survival analysis of the optical brightness of GRB host galaxies

We studied the unbiased optical brightness distribution which was calculated from the survival analysis of host galaxies and its relationship with the Swift GRB data of the host galaxies observed by the Keck telescopes. Based on the sample obtained from merging the Swift GRB table and the Keck optical data we also studied the dependence of this distribution on the data of the GRBs. Finally, we compared the HGs distribution with standard galaxies distribution which is in the DEEP2 galaxies catalog.Comment: Swift: 10 Years of Discovery. Conference paper. 2-5 December 2014. La Sapienza University, Rome, Ital

Intrinsic optical dichroism in the chiral superconducting state of Sr2_{2}RuO4_{4}

We present an analysis of the Hall conductivity $\sigma_{xy}(\omega, T)$ in time reversal symmetry breaking states of exotic superconductors. We find that the dichroic signal is non-zero in systems with inter-band order parameters. This new intrinsic mechanism may explain the Kerr effect observed in strontium ruthenate and possibly other superconductors. We predict coherence factor effects in the temperature dependence of the imaginary part of the ac Hall conductivity $Im\sigma_{xy}(\omega, T)$, which can be tested experimentally.Comment: 4+ pages, 4 figures, published versio

Comparing the observed properties of the GRBs detected by the Fermi and Swift satellites

We studied the distribution of the GRBs, observed by the Fermi satellite, in the multidimensional parameter space consisting of the duration, Fluence, Peak flux and Peak energy (if it was available). About 10% of the Fermi bursts was observed also by the Swift satellite. We did not find significant differences between the Peak flux and Peak energy of GRBs observed and not observed also by the Swift satellite. In contrast, those GRBs detected also by the Swift satellite had significantly greater Fluence and duration. We did a similar study for the GRBs detected by the Swift satellite. About 30% percent of these bursts was also measured by the Fermi satellite. We found a significant difference in the Fluence, Peak flux and Photon index but none in duration. These differences may be accounted for the different construction and observing strategy of the Fermi and Swift satellites.Comment: 7th Huntsville Gamma-Ray Burst Symposium, GRB 2013: paper 5 in eConf Proceedings C130414