Study of CMS sensitivity to neutrinoless τ\tau decay at LHC

The Large Hadron Collider (LHC), scheduled to start operation in 2006, is foreseen to provide in the first year of running a total of $\sim 10^{12}$ $\tau$ leptons. CMS (Compact Muon Solenoid) is a general-purpose experiment designed to study proton-proton and heavy-ion collisions at LHC. Even if the Susy particles and Higgs searches togheter with the B-physics present its main goal, the large amount of $\tau$-lepton, could allow a systematic study of tau-physics. We have performed a full simulation of CMS using GEANT 3 package and the object-oriented reconstruction program ORCA to study the sensitivity to neutrinoless tau decay $\tau \to \mu^+ \mu^- \mu^-$ and $\tau \to \mu \gamma$. We present the analysis developed for these channels and the results obtained.Comment: Invited talk at the seventh international Workshop on tau lepton physics (TAU02), Santa Cruz, Ca, Usa, September 2002 10 pages 15 eps figure

Closing Talk: QCD Moriond 2006

I comment on some theoretical work presented at QCD Moriond 2006.Comment: 11 pages, 9 figure

Growth of covariant perturbations in the contracting phase of a bouncing universe

In this paper we examine the validity of the linear perturbation theory near a bounce in the covariant analysis. Some linearity parameters are defined to set up conditions for a linear theory. Linear evolution of density perturbation and gravitational waves have been computed previously. We have calculated the vector and scalar induced parts of the shear tensor. For radiationlike and dustlike single fluid dominated collapsing Friedmann-Lemaitre-Robertson-Walker background it is shown that the linearity conditions are not satisfied near a bounce.Comment: 9 pages, final versio

Inhomogeneity effects in Cosmology

This article looks at how inhomogeneous spacetime models may be significant for cosmology. First it looks at how the averaging process may affect large scale dynamics, with backreaction effects leading to effective contributions to the averaged energy-momentum tensor. Secondly it considers how local inhomogeneities may affect cosmological observations in cosmology, possibly significantly affecting the concordance model parameters. Thirdly it presents the possibility that the universe is spatially inhomogeneous on Hubble scales, with a violation of the Copernican principle leading to an apparent acceleration of the universe. This could perhaps even remove the need for the postulate of dark energy.Comment: 29 pages. For special issue of CQG on inhomogeneous cosmologie

On the paradox of Hawking radiation in a maximally extended Schwarzschild solution

This paper considers the effect of Hawking radiation on an eternal black hole - that is. a maximally extended Schwarzschild solution. Symmetry considerations that hold independent of the details of the emission mechanism show there is an inconsistency in the claim that such a blackhole evaporates away in a finite time. In essence: because the external domain is static, there is an infinite time available for the process to take place, so whenever the evaporation process is claimed to come to completion, it should have happened earlier. The problem is identified to lie in the claim that the locus of emission of Hawking radiation lies just outside the globally defined event horizon. Rather, the emission domain must be mainly located inside the event horizon, so most of the Hawking radiation ends up at this singularity rather than at infinity and the black hole never evaporates away. This result supports a previous claim [arXiv:1310.4771] that astrophysical black holes do not evaporate.Comment: 26 pages, 7 figures, 2 tables. arXiv admin note: text overlap with arXiv:1310.477