### Conveners

#### The Early Universe: Block 1

- Stefano Ansoldi (University of Udine)

#### The Early Universe: Block 2

- Stefano Ansoldi (University of Udine)

### Description

This parallel session focus is on theoretical (both, analytic and computational) results that advance our understanding of the physics of the early universe. Contributions are welcome on a wide range of topics including, but not limited to, inflation (related open problems, models and predictions), alternatives to inflation and their viability (in, both, general relativity and/or modified gravity theories), quantum fields (theory and phenomenology) on cosmological backgrounds, and, in general, technical and conceptual proposals that address open fundamental issues in the physics of the early universe. This session aims to be complementary to AT1, BS1, and the CM1-4 sessions on the cosmic microwave background and the lambda cold dark matter models.

We reduplicate the Book “Dark Energy” by M. Li, X-D. Li, and Y. Wang, given zero-point energy calculation with an unexpected “length’ added to the ‘width’ of a graviton wave just prior to specifying the creation of ‘gravitons’, using the Rosen and Israelit model of a nonsingular universe. In doing so we are in addition to obtaining a wavelength 10^30 times greater than Planck’s length so we...

The origin of primordial magnetic fields and baryon asymmetry of the Universe are still unresolved issues and require physics beyond the standard models of cosmology and particle physics. Since both require physics beyond the standard model, there is a possibility that the same new physics can solve both.

In this talk, I will discuss our model, where non-minimal coupling to the Riemann...

We look at Viutilli (1999) write up of a generalized schrodinger equation with its Ricci scalar inclusion, in curved space-time. This has a simplified version in Pre Planckian regime, which leads to comparing a resultant admissible wave function with Bohmian reformulations of quantum physics. As was done earlier, we compare this result with a formulation of a modified ‘Poisson’ equation from...

Due to the general covariance of the Einstein equations and

conservation laws, the linearized equations have solutions which are

gauge-dependent and have, therefore, no physical significance.

In this talk I will show that the decomposition theorems for symmetric

second-rank tensors of the maximally symmetric subspaces of constant

time imply that there are exactly two, unique,...

Due to the quantum origin of primordial perturbations and the energy scales of the primordial plasma, the early universe is an ideal setup for the interplay between gravity, quantum physics and thermodynamics. Even though most of the expansion history of the universe is adiabatic, irreversible processes play a role in key cosmological events. In this talk I will discuss results and ongoing...

We implement Polymer Quantum Mechanics on the Hamiltonian formulation of the isotropic Universe in both the representations of the standard Ashtekar-Barbero-Immirzi connection and of a new generalized coordinate conjugate to the Universe volume. The resulting morphology is a bouncing cosmology; when quantizing the volume-like variable the Big Bounce is an intrinsic cut-off on the cosmological...

It is argued that the past of the Universe, extrapolated from standard physics and measured cosmological parameters, might be a non-singular bounce without any exotic hypothesis. We show that, in this framework, stringent constraints can be put on the reheating temperature and number of inflationary e-folds. We draw some conclusions about the shape of the inflaton potential and raise the...

Observations of the 21 cm signal through intensity mapping techniques are expected in the near future. This new observable will allow to probe evolution of the Universe in a very wide redshift range, from the dark ages, through the epoch of reionization up to the present time. We constrain cosmological parameters from forecast measurements of the 21 cm signal power spectrum $P_{21}(k,z)$...

From the assumption that the slow roll parameter

ε has a Lorentzian form as a function of the e-folds number N, a successful model of a quintessential inflation is obtained. The form corresponds

to the vacuum energy both in the inflationary and in the

dark energy epochs and satisfies the condition to climb from

small values of ε to 1 at the end of the inflationary epoch.

We find the...

The theory of primordial inflation has been highly successful in resolving theoretical difficulties of standard FRW cosmology. Moreover, many of the general predictions of inflation have been confirmed by observation. However, higher precision measurements of the cosmic microwave background (CMB) now disfavor many inflation-driving potentials due to a suppression of the tensor-to-scalar...

Over the last decade, experimental physics and observational cosmology have made many fundamental discoveries: gravitational waves (LIGO), Higgs bosons (LHC), photon condensates with rest energy and rest mass trapped in "mirror cavities" (Bonn University).

Through these remarkable results, Nature suggests that at pressures and temperatures well above the Higgs field level (246 GeV), only the...

The Generalized Chaplygin Gas (GCG) model is characterized by the equation of state P = −A ρ^{−α}, where A>0 and α < 1. The model has been extensively studied due to its interesting properties and applicability in several contexts, from late-time acceleration to primordial inflation. Nonetheless we show that the inflationary slow-roll regime cannot be satisfied by most of the parameter space...