International Journal of Modern Physics A

The direct discovery of gravitational waves opens of new avenues for exploring fundamental microscopic physics. In this presentation, I will illustrate this by obtaining the stringent bounds on the scale of quantum fuzziness of hypothetical noncommutative space–time. I also discuss how future observations of stochastic gravitational wave background can shed light on the nature of the Higgs mechanism of the electroweak symmetry breaking and the related cosmological phase transition.

Recent detections of gravitational waves by the LIGO detectors herald a new era of observational astronomy. Previously invisible objects and phenomena may now be uncovered through their gravitational interaction. Observation of gravitational waves allows one to explore the extremes of the Universe and study astronomy and fundamental physics like never before. This article gives a brief overview of the detection process, from the production of the data to their physical implications.

Advanced Virgo is the French–Italian second generation laser gravitational wave detector, successor of the Initial Virgo. This new interferometer keeps only the infrastructure of its predecessor and aims to be ten times more sensitive, with its first science run planned for 2017. This article gives an overview of the Advanced Virgo design and the technical choices behind it. Finally, the up-to-date progresses and the planned upgrade for the following years are detailed.

We review recent developments in the construction of heterotic and type II string field theories and their various applications. These include systematic procedures for determining the shifts in the vacuum expectation values of fields under quantum corrections, computing renormalized masses and S-matrix of the theory around the shifted vacuum and a proof of unitarity of the S-matrix. The S-matrix computed this way is free from all divergences when there are more than 4 noncompact space–time dimensions, but suffers from the usual infrared divergences when the number of noncompact space–time dimensions is 4 or less.

In the simplest version of a $Q_6$ flavored supersymmetric model, we analyze the leptonic masses and mixings in the framework of a soft breaking of the $\mu \leftrightarrow \tau$ symmetry. This breaking is controlled by the inequality $m_{e\tau }\ne m_{e\mu }$ in the effective neutrino mass. As a consequence of this breaking, the reactor and atmospheric angles are deviate from $0^{\circ }$ and $45^{\circ }$, respectively. Such deviations can be enhanced or suppressed by the CP parities in the Majorana phases, so an analytic study is carried out to remark their importance to constrain the free parameters that accommodate the mixing angles. The normal hierarchy is completely discarded in this model, the inverted hierarchy is less favored than the degenerate one where the reactor and atmospheric angles are in good agreement with the experimental data. Additionally, the model predicts defined regions for the effective neutrino mass decay, the neutrino mass scale and the sum of the neutrino masses in the inverted and degenerate mass spectra. Thus, this model may be testable by future experiments that focus on neutrinoless double beta decay.

We discuss a generalization of the Snyder model compatible with undeformed Lorentz symmetries, which we describe in terms of a large class of deformations of the Heisenberg algebra. The corresponding deformed addition of momenta, the twist and the R-matrix are calculated to first order in the deformation parameters for all models. In the particular case of the Snyder realization, an analytic formula for the twist is obtained.

In light of a recent paper, we revisit the Compton scale region and point out that in this region there is stochastic behavior which can be modeled by Ito’s method. All these lead to a QCD and quark-like behavior completely consistent with known empirical facts.

We calculate new corrections to the braneworld dynamics, lying in a 5D Schwarzschild–de Sitter black hole, generalizing the result of Nojiri, Odintsov and Ogushi (NOO). The NOO entropy effect is based on the logarithmic correction to the bulk entropy firstly calculated by Mukherji and Pal. We calculate higher order contributions to the brane worldsheet. The extra terms obtained lead to interesting implications in brane cosmology. In particular, new entropic terms rapidly disappear in the late Universe while exploding in the very early Universe. In particular, we show that they may trigger a cosmological bounce in the very early Universe. On the other hand, they contribute to the cosmological expansion in the late Universe. We also discuss a scenario in which the BLK anisotropies are washed out, toward a new ekpyrotic brane cosmology.

In a previous work a novel parametrization was proposed for the $pp$ and $\bar{p}p$ total cross-sections. Here, results are presented for the updated analysis with taking into account the recent data from accelerator experiments as well as from cosmic ray measurements. The analytic parametrizations suggested within axiomatic quantum field theory (AQFT) provide the quantitative description of energy dependence of global scattering observables with robust values of fit parameters. Based on the fit results the estimations are derived for the total cross-section and the $\rho$ parameter in elastic $pp$ scattering at various $\sqrt{s}$ up to energy frontier $\sqrt{s}=10$ PeV which can be useful for present and future hadron colliders as well as for cosmic ray measurements at ultra-high energies.

Sivers effect is describing the correlation between the transverse polarization of nucleon and the transverse momentum, $k_{\perp }$, of its unpolarized constituent partons. This effect is an outstanding subject and in this regard, a great deal in recent years has been considered from experimental and phenomenological points of view. It also plays an essential role to extend our understanding from nucleon structure. Semi-inclusive DIS (SIDIS) process provides us an opportunity to access to Sivers function which is dependent on transverse momentum of partons. In this paper, for the first time the covariant parton model is used to deliver us the $k_{\perp }$ and $x$ dependence part of Sivers function. Based on this model, this combinatory dependence is arising out from the HERAPDF parametrization group. In this paper the other required parametrized functions in Sivers function is also changed with respect to Ref. 1. The unknown parameters which exist in Sivers function can be extracted, doing a global fit over the recent available experimental data, including HERMES, COMPASS and JLAB collaborations for the single spin asymmetry (SSA) in ${\pi }^{-}$ and ${\pi }^{+}$ meson production as well as kaon production to constrain the evolved strange quark. This is done, considering advanced mathematical manipulations to overcome the difficulties which exist to compute the required multiple integrals and finally employing the CERN MINIUTE program to do a global fit. Our results for SSA are in good agreement with the available experimental data. For more confirmation a comparison between our results and the ones from Ref. 2 is also done.