I will show how quasinormal modes of black holes can be used to investigate new physics and quantum gravity. Some results on isospectrality will also be underlined.

Causal Dynamical Triangulations (CDT) is a lattice model which provides a non-perturbative, background independent formulation of four-dimensional quantum gravity. It provides an emergent background geometry and one can study the quantum fluctuations around this background geometry. The model has second order phase transition lines in the bare coupling constants. These transition lines may be...

In this talk I plan to review the cosmological paradigm of nonsingular bounces, which is often regarded as an alternative to inflation in describing the very early universe. Such a scenario, while can avoid the big bang spacetime singularity, often suffers from conceptual challenges, namely, the dangerous growth of anisotropic stress, the possibly existence of ghosts, gradient instabilities or...

Our universe is fulfilled by stochastic background of gravitational waves with a large range of frequencies, which may have various astrophysical/cosmological origins in the early universe. As our universe is transparent to gravitational wave, it is a fossil recording the information of its generation and how our universe evolves. In this talk I will briefly review the stochastic background of...

Gravitational waves (GWs) are unavoidably induced at second order in cosmological perturbation theory. The so-called induced GWs are a crucial counterpart of the primordial black hole scenario and might be observable by future space based gravitational waves detectors. However, only the generation during radiation and matter domination eras has been analytically studied. In this talk, I will...

An open question in quantum gravity is if and how small scale quantum fluctuations and inhomogeneities behave in such a way that at some larger scale they can be well approximated by a classical geometry with some number of exact symmetries. Causal Dynamical Triangulation (CDT) is a non-perturbative approach to quantum gravity, based on a lattice regularisation of space-time, in which these...

Understanding the laws of inflation can shed light on the processes that govern physics at very high energy scales, beyond current experimental limits. In particular, the characterisation and detection of primordial gravitational waves produced during inflation can be an excellent test for the particle content of the very early universe. We consider an inflationary realisation whose tensor...

We present recent work on disformal transformations in the context of modified gravity based on the teleparallel equivalent of general relativity, and applications to f(T) gravity. We show the implications a disformal transformed tetrad has in the main geometric quantities, and explore the relation with the loss of local Lorentz invariance and the issue of the degrees of freedom in these...

Searching for minuscule departures from exact Lorentz symmetry is an excellent

probe of new physics; recently, there has been a large increase in gravity tests

of Lorentz symmetry. In the context of the Standard-Model Extension

effective field theory, we discuss and summarise recent developments in the search

for Lorentz violation. We also present recent work done in Lorentz-violating...

We present the quantum model of the asymptotic dynamics underlying

he Belinski-Khalatnikov-Lifshitz (BKL) scenario. The classical BKL

scenario concerns generic singularity of general relativity. The quantum

BKL scenario shows that gravitational singularity can be replaced by

quantum bounce that presents a unitary evolution of considered

gravitational system. Our results suggest that...