### Conveners

#### Cosmology & Dark Energy

- Neelima Sehgal
- Vivian Miranda (University of Arizona)
- Michael Troxel (Duke University)

#### Cosmology & Dark Energy

- Neelima Sehgal
- Michael Troxel (Duke University)
- Vivian Miranda (University of Arizona)

### Description

parallel sessions

The robustness of inflation to inhomogeneous initial conditions for matter fields and the spacetime metric is under investigation. If inflationary expansion fails to begin under sufficiently inhomogeneous initial conditions, such that inflation requires fine-tuning of its initial state to occur, then its naturalness is challenged. I will present results for the range of initial conditions...

Models of axion inflation based on a single cosine potential require the axion decay constant to be super-Planckian in size. However, a super-Planckian axion decay constant is disfavored in quantum gravity and in strings, and by the weak gravity conjecture. Here we propose a coherent enhancement mechanism which can produce an effective axion decay constant which is super Planckian even if the...

Inflation predicts that quantum fluctuations determine the large scale structure of the Universe. This raises the striking possibility that quantum mechanics, developed to describe nature at short distances, can be tested by studying nature at its most immense -- cosmology. By fully accepting the inflationary paradigm we realize this possibility. A nonlinear generalization of quantum...

A theoretical description of cosmological inflation,

dark energy (cosmological constant) and dark

matter in supergravity is non-trivial. I review the

standard procedures and propose the new ones

based on recent developments in supergravity theory.

Phenomenological aspects of dark matter in high-scale SUSY

breaking scenario are also briefly discussed.

P.S. Based on recent publications of...

The field of physics has been built on the scientific method where our greatest theories have been developed from a well-established foundation. However, so far, no derivations stemming from our current mathematics expressing our most validated theories has been able to reveal the nature of “dark” energy. It may be time to consider... What if it is impossible to derive the nature of dark...

The existing set of type Ia supernovae (SNe Ia) is now sufficient to detect oscillatory deviations from the canonical $\Lambda$CDM cosmology.

We determine that the Fourier spectrum of the Pantheon data set of spectroscopically well-observed SNe Ia is consistent with the predictions of $\Lambda$CDM.

We also develop and describe two complementary techniques for using SNe Ia to constrain those...

Galaxy clustering from ongoing and forthcoming large galaxy surveys plays an important role in understanding the acclerated cosmic expansion, through the measurements of baryon acoustic oscillations (BAO) and the redhshift-space distortions (RSD). The latter can be used to infer the linear structure growth rate in the universe, which can constrain the equation of state of dark energy and test...

The Dark Energy Survey (DES) has provided world leading measurements in multiple probes of the late time universe. Using probes of weak gravitational lensing, galaxy clustering, cluster cosmology and supernovae from the first year of observations, DES was able test the Lambda CDM model with greater constraining power than any other individual galaxy survey. I will present the latest updates...

Galaxy clusters have been established as an important tool to study the matter distribution, the formation and evolution of the structures in the Universe with great potential to be one of the most powerful cosmological probes. To achieve this, we need to understand the systematics involved in the cluster mass calibration, which is the current dominating source of uncertainties for using...

Hubble’s law, states that recession speed, vR, is equal to a new speed, H0D, where H0 is Hubble’s constant and D is the distance to the inter-galactic photon source.

The “Hubble Equality” is vR = H0D.

The relativistic Doppler Effect is used to relate the intergalactic photon red-shift to recession speed.

When the relativistic Doppler equation is solved for β, (vR /c), it is well-known...