Emerging Theories in Cosmology: Insights from Recent Research

Recent research has opened new avenues in cosmology, particularly in understanding cosmic structures and dark energy. A study published on ArXiv titled "Forecasting Primordial Non-Gaussianity from UNIONS Lyman-Break Galaxies and Planck CMB lensing" explores how primordial non-Gaussianities, characterized by $f_{NL}^{loc}$, can provide insights into the physics of inflation. This research utilizes cross-correlation techniques between high-redshift Lyman-Break Galaxies (LBGs) and the Cosmic Microwave Background (CMB) lensing potential, aiming to improve the precision of measuring $f_{NL}^{loc}$ to $20$ after spectroscopic follow-up with the Dark Energy Spectroscopic Instrument (DESI) during its next phase starting in 2029.

Another significant advancement is highlighted in a separate study focusing on the kinetic Sunyaev-Zel'dovich (kSZ) effect. Titled "Astrophysical constraints from future measurements of the kinetic Sunyaev-Zel'dovich power spectrum," this research suggests that high-precision measurements of the CMB will enable the detection of small-scale secondary anisotropies, which can provide crucial information about the Epoch of Reionisation. By linking the kSZ power spectrum to the properties of ionising sources, scientists aim to access details about ionised regions and simultaneously enhance CMB analyses. The study indicates that future CMB experiments could yield meaningful constraints on astrophysical model parameters, including the ionising escape fraction with an expected 14% relative error.

In another groundbreaking effort, researchers have measured the Hubble constant, $H_0$, using data from the DESI Data Release 1. The study titled "A measurement of $H_0$ from DESI DR1 using energy densities" presents a new approach that is independent of standard rulers and robust against pre-recombination modifications such as Early Dark Energy. By calibrating the total energy density of the universe and validating their method against a suite of N-body mocks, the researchers determined $H_0 = 69.0 \\pm 2.5$ km s$^{-1}$ Mpc$^{-1}$, which aligns with existing early and late-time determinations of the Hubble constant. The study anticipates that future data from DESI and the Euclid mission will further contribute to resolving the Hubble tension.

These studies collectively represent a significant push towards unraveling key cosmological mysteries, focusing on the nature of dark energy, the structure of the universe, and the fundamental parameters governing its expansion. They highlight the importance of observational data and advanced methodologies in enhancing our understanding of the cosmos, paving the way for new theoretical frameworks in cosmology.