RKR_K and $K^+\rightarrow\pi^+\nu\bar{\nu} with NA62 at CERN SPS

Recent results a future prospects of the NA62 experiment at CERN SPS are presented. The NA62 experiment performed the most precise measurement of the ratio $R_K$ of the $K^+\rightarrow e^\pm\nu$ and K^+\rightarrow \mu^\pm\nu$decay rates using the full data set collected in 2007. The result is in agreement with the Standard Model expectation. The ultra-rare decay$K^+\rightarrow\pi^+\nu\bar{\nu}$is an excellent processes to make tests of new physics at the highest scale complementary to the LHC thanks to their theoretically cleanness. The NA62 experiment at CERN SPS aims to collect of the order of 100$K^+\rightarrow\pi^+\nu\bar{\nu}$ events in two years of data taking, keeping the background at the level of 10%.Comment: Proceedings of CKM 2012, the 7th International Workshop on the CKM Unitarity Triangle, University of Cincinnati, USA, 28 September - 2 October 201

Contracting rigid germs in higher dimensions

Following Favre, we define a holomorphic germ f:(C^d,0) -> (C^d,0) to be rigid if the union of the critical set of all iterates has simple normal crossing singularities. We give a partial classification of contracting rigid germs in arbitrary dimensions up to holomorphic conjugacy. Interestingly enough, we find new resonance phenomena involving the differential of f and its linear action on the fundamental group of the complement of the critical set.Comment: 30 pages, 0 figure

Reflections After Seattle

The WTO cannot operate in isolation from the concerns of the world in which it exists. Our ability to advance trade, build a stronger system, and move forward in a new round will hinge on our ability to make simultaneous progression on these issues. How do we do this? First, we must move toward a more collective leadership, one that reflects the reality of a multipolar world and especially the emergence of developing-country powers. Second, we need to look at the policy challenges we face as pieces of an interconnected puzzle. Third, we need a new forum for the management of these complex issues, one that is truly representative of the new global realities and that brings world leaders together to tackle an expanded policy agenda and the new challenges of globalization. Fourth, there is a need for a clear mandate from leaders to promote a common global strategy and common global actions

Sagnac Effect, Ring Lasers and Terrestrial Tests of Gravity

Light can be used as a probe to explore the structure of space-time: this is usual in astrophysical and cosmological tests, however it has been recently suggested that this can be done also in terrestrial laboratories. Namely, the GINGER project aims at measuring post-Newtonian effects, such as the gravito-magnetic ones, in an Earth based laboratory, by means of a ring lasers array. Here, we first review the theoretical foundations of the Sagnac Effect, on which ring lasers are based, and then we study the Sagnac Effect in a terrestrial laboratory, emphasizing the origin of the gravitational contributions that GINGER aims at measuring. Moreover, we show that accurate measurements allow to set constraints on theories of gravity different from General Relativity. Eventually, we describe the experimental setup of GINGER.Comment: 24 pages, 1 figure; accepted for publication in Galaxies, Special Issue "Advances in Gravitational Research

Light bending in f(T)f(T) gravity

In the framework of $f(T)$ gravity, we focus on a weak-field and spherically symmetric solution for the Lagrangian $f(T)=T+\alpha T^{2}$, where $\alpha$ is a small constant which parameterizes the departure from General Relativity. In particular, we study the propagation of light and obtain the correction to the general relativistic bending angle. Moreover, we discuss the impact of this correction on some gravitational lensing observables, and evaluate the possibility of constraining the theory parameter $\alpha$ by means of observations. In particular, on taking into account the astrometric accuracy in the Solar System, we obtain that $|\alpha| \leq 1.85 \times 10^{5}\, \mathrm{m^{2}}$; this bound is looser than those deriving from the analysis of Solar System dynamics, e.g. $|\alpha| \leq 5 \times 10^{-1}\, \mathrm{m^{2}}$, $|\alpha| \leq 1.8 \times 10^{4}\, \mathrm{m^{2}}$ or $|\alpha| \leq 1.2 \times 10^{2}\, \mathrm{m^{2}}$ . However we suggest that, since the effect only depends on the impact parameter, better constraints could be obtained by studying light bending from planetary objects.Comment: 14 pages, 1 figure; revised to match the version accepted for publication in IJMP