Related papers: Late-time vacuum phase transitions: Connecting sub…
The suggestion that we occupy a privileged position near the centre of a large, nonlinear, and nearly spherical void has recently attracted much attention as an alternative to dark energy. Putting aside the philosophical problems with this…
We review the perhaps most exciting phenomenology of models with extra spatial dimensions and Planck scale near TeV: the production of mini black holes in ultrahigh energy particle collisions, and the discovery potential of cosmic…
A first-order phase transition could occur in the late universe when vacuum energy begins dominating the energy density ($z \lesssim 0.3$) and convert some latent heat into other forms such as invisible radiation. This generic possibility…
We solve dynamical equations of motion to determine the conditions under which an over-dense region in the early universe will lead to collapse to a black hole, starting from horizon crossing of the over-dense region to the point of…
We reexamine production of primordial black holes in a supercooled phase transition. While a mere overdensity associated with a surviving false-vacuum patch does not imply formation of a black hole, it is possible for such a patch to evolve…
Phase transitions are part of everyday life, yet are also believed to be part of the history of our universe, where the nature of particle interactions change as the universe settles into its vacuum state. The discovery of the Higgs, and…
New dark vector bosons that couple very feebly to regular matter can be created in the early universe and decay after the onset of big bang nucleosynthesis (BBN) or the formation of the cosmic microwave background (CMB) at recombination.…
We compare the evolution of voids formed under the standard cosmological model and two alternative cosmological models. The two models are a quintessence model ($\phi$CDM) and a Coupled Dark Matter-Dark Energy (CDE) model, both of which…
In the present thesis, the author reviews the physics of cosmological first-order phase transitions that may have occured shortly after the Big Bang. Such transitions proceed via the nucleation and expansion of true vacuum bubbles and give…
In these notes we present a summary of existing ideas about phase transitions of black hole spacetimes in semiclassical gravity and offer some thoughts on three possible scenarios by which these transitions could take place. Our first theme…
We study the possibility to populate the dark sector through a phase transition. We will consider secluded dark sectors made of gauge theories, Randall-Sundrum scenarios and conformally coupled elementary particles. These sectors have in…
The fundamental constants at recombination can differ from their present-day values due to degeneracies in cosmological parameters, raising the possibility of yet-undiscovered physics coupled directly to the Standard Model. We study the…
We study the cosmological implications of the minimal non-linear realisation of scale invariance within the Standard Model (SM). This framework provides a technically natural explanation for the hierarchy between the Planck scale and the…
We consider the generic scenario of dark energy which arises through the latent heat of a hidden sector first order cosmological phase transition. This field could account for the extra radiation degree of freedom suggested by the CMB. We…
We investigate the possibility for cosmic ray experiments to discover non-thermal small black holes with masses in the TeV range. Such black holes would result due to the impact between ultra high energy cosmic rays or neutrinos with nuclei…
The Standard Model and its extensions predict multiple phase transitions in the early universe. In addition to the electroweak phase transition, one or several of these could occur at energies close to the weak scale. Such phase transitions…
Deep surveys indicate a bubbly structure of cosmological large scale which should be the result of evolution of primordial density perturbations. Several models have been proposed to explain origin and dynamics of such features but, till…
Nearly conformal dynamics at the TeV scale as motivated by the hierarchy problem can be characterized by a stage of significant supercooling at the electroweak epoch. This has important cosmological consequences. In particular, a common…
Interacting dark sectors may undergo changes in the number of their relativistic species during the early universe, due to a mass threshold $m$ (similar to changes in the Standard Model bath), and in doing so affect the cosmic history. When…
We investigate the formation of primordial black holes (PBHs) through delayed vacuum decay during slow cosmic first-order phase transitions. Two specific models, the polynomial potential and the real singlet extension of the Standard Model,…