TITLES AND ABSTRACTS First Name: Andrea Surname: Addazi Affiliation: Fudan University (Shanghai) Quantum Vacuum & Quantum black holes: two aspects of the same question ---------------------------------------------------------------------------------------- Quantum vacuum and Quantum black holes may be considered as two aspects of the same problem. First of all, we will show how virtual black hole pairs provide a planckian contribution to the vacuum energy which screens the contribution coming from Standard Model vacuum energy. Second, we will move on the possible relation of dark energy and (Anti)evaporation instabilities in the framework of f(R)-gravity, In this case, a model for cosmology may provide insightful intuitions on the black hole thermodynamics and the information paradox. First Name: Imanol Surname: Albarran Affiliation: Universidade da Beira Interior The quantum realm of the "Little Sibling" of the Big Rip singularity ---------------------------------------------------------------------------------------- We analyse the quantum behaviour of the Little Sibling of the Big Rip singularity (LSBR). The quantisation is carried within the geometrodynamical approach given by the Wheeler- DeWitt(WDW)equation. The classical model is based on a Friedmann-Lemaître- Robertson-Walker Universe filled by a perfect fluid that can be mapped to a scalar field with phantom character. We analyse the WDW equation in two setups. In the fi rst step, we consider the scale factor as the single degree of freedom, which from a classical perspective parametrises both the geometry and the matter content given by the perfect fluid. We then solve the WDW equation within a WKB approximation, for two factor ordering choices. On the second approach, we consider the WD equation with two degrees of freedom: the scale factor and a scalar fi eld. We solve the WDW equation, with the Laplace-Beltrami factor-ordering, using a Born-Oppenheimer approximation. In both approaches, we impose the DeWitt (DW) condition as a potential criterion for singularity avoidance. We conclude that in all the cases analysed the DW condition can be verified, which might be an indication that the LSBR can be avoided or smoothed in the quantum approach. First Name: Oleg Surname: Antipin Affiliation: Institut Rudjer Boskovic Revisiting the decoupling effects in the running of the Cosmological Constant ---------------------------------------------------------------------------------------- We discuss the decoupling effects associated with heavy particles in the renormalisation group running of the vacuum energy in a mass-dependent renormalization scheme. We find the running of the vacuum energy stemming from the Higgs condensate in the entire energy range and show that it behaves as expected from the simple dimensional arguments meaning that it exhibits the quadratic sensitivity to the mass of the heavy particles in the infrared regime. The consequence of such a running to the fine-tuning problem with the measured value of the Cosmological Constant is analyzed and the constraint on the mass spectrum of a given model is derived. We show that in the Standard Model (SM) this fine-tuning constraint is not satisfied while in the massless theories this constraint formally coincides with the well known Veltman condition. We also provide a remarkably simple extension of the SM where saturation of this constraint enables us to predict the radiative Higgs mass correctly. Generalization to constant curvature spaces is also given. First Name: Manuel Surname: Asorey Affiliation: Universidad de Zaragoza Infrared and ultraviolet problems in QFT and Quantum Gravity ---------------------------------------------------------------------------------------- First Name: Alexander Surname: Balakin Affiliation: Kazan Federal University, Institute of Physics Rheological models of the cosmic dark fluid ---------------------------------------------------------------------------------------- Based on analogy with classical theory of thermo-visco-elasticity, we formulate rheological models of evolution of the cosmic dark fluid. In the context of homogeneous cosmological models, the simplest rheological equations of state for the interacting dark energy and dark matter take into account the time delay in the evolutionary processes. Mathematically, these time delay effects can be described in terms of convective derivatives and convolution integrals of the Volterra type, thus the equations of state are considered to be the integro-differential equations. Applications to the Friedmann-type models and Bianchi-I type models are considered; the five-parameter family of exact solutions is obtained, classified and analyzed. First Name: José Surname: Beltran Jimenez Affiliation: Universidad Autónoma de Madrid Theoretical aspects of Born-Infeld inspired gravity with cosmological applications. ---------------------------------------------------------------------------------------- Abstract: In order to regularize the energy of point-like charged particles, Born and Infeld introduced a modification of the Maxwell Lagrangian that naturally imposes an upper bound on electromagnetic fields. Similar ideas can be applied to gravity to resolve the GR singularities. I will discuss some general theoretical aspects of these theories (which are shared by more general metric-affine theories) as well as some cosmological applications, with emphasis in non-singular and inflationary solutions. First Name: Mariam Surname: Bouhmadi-López Affiliation: University of the Basque Country Cosmological perturbations of the late-time Universe. ---------------------------------------------------------------------------------------- We carry out an analysis of the cosmological perturbations in general relativity for different models which are good candidates to describe the current acceleration of the Universe. These different set-ups are described classically by perfect fluids with a quintessence or a phantom nature and represent deviations from the most widely accepted ΛCDM model. In the phantom case, each of the models under study induce different future singularities or abrupt events known as (i) Big Rip, (ii) Little Rip and (iii) Little Sibling of the Big Rip. With the aim to find possible footprints of the different scenarios, we not only obtain the evolution of the cosmological scalar perturbations but also calculate the matter power spectrum for each model. We constrain observationally these models using several measurements of the growth rate function, more precisely fσ8, and compare our results with the observational ones. First Name: Antonio Surname: Capolupo Affiliation: Università di Salerno Dark Matter and Dark Energy Induced by Vacuum Condensates ---------------------------------------------------------------------------------------- It is shown that the vacuum condensate induced bymany phenomena behaves as a perfect fluid which, under particular conditions, has zero or negative pressure. In particular, the condensates of thermal states of fields in curved space and of mixed particles have been analyzed. It is shown that the thermal states with the cosmic microwave radiation temperature and the Unruh and the Hawking radiations give negligible contributions to the critical energy density of the universe, while the thermal vacuum of the intercluster medium could contribute to the dark matter, together with the vacuum energy of fields in curved space-time and of mixed neutrinos. Moreover, a component of the dark energy can be represented by the vacuum of axion-like particles mixed with photons and superpartners of neutrinos.The formal analogy among the systems characterized by the condensates can open new scenarios in the possibility of detecting the dark components of the universe in table top experiments. First Name: Salvatore Surname: Capozziello Affiliation: Università Federico II di Napoli Addressing the missing matter problem in galaxies through a new fundamental gravitational radius ---------------------------------------------------------------------------------------- We demonstrate that the existence of a Noether symmetry in f(R) theories of gravity gives rise to a further gravitational radius, besides the standard Schwarzschild one, determining the dynamics at galactic scales. By this feature, it is possible to explain the baryonic Tully-Fisher relation and the rotation curve of gas-rich galaxies without the dark matter hypothesis. First Name: Po-Wen Surname: Chang Affiliation: National Taiwan University Rapid Oscillation of Gravitational Constant in the Scalar-Tensor Theory of Gravity: the early-time constraints on its induced energy density from cosmology ---------------------------------------------------------------------------------------- In the scalar-tensor theory of gravity, the concept of gravitational constant G can be replaced with a scalar field non-minimally coupled to gravity. It turns out to be an additional degree of freedom compared to general relativity and is possible to induce periodic oscillations in G by a homogeneous and isotropic massive scalar field ϕ. In this research, we show that the equation of motion of ϕ can be cast into a fairly graceful formula and the dissipation rate of its effective energy density could behave differently during the cosmic evolution, which depends on the strength of non-minimal coupling, mass of ϕ and the cosmic expansion rate. Realizing the dynamics of ϕ, we find that we could obtain a loose upper bound of the effective energy density from cosmology by assuming specific properties of the G oscillation