Conveners
Astoparticles and CMB: AST 3J
- Ivan Esteban (CCAPP, Ohio State University)
- Kevin Huffenberger (Florida State University)
Astoparticles and CMB: AST 4J
- Sridhara Dasu (University of Wisconsin Madison (US))
- Barmak Shams Es Haghi (University of Utah)
Astoparticles and CMB: AST 6E
- Todd Adams (Florida State University (US))
- Kristi Engel (University of Maryland College Park)
Ultralight axions (ULA), whose masses can lie in a wide range of values and can be even smaller than $10^{−28}$ eV, are generically predicted in UV theories such as string theory. In the cosmological context, the early Universe may have gotten filled with a network of ultralight axion (ULA) cosmic strings which, depending upon the mass of the axion, can survive till very late times. If the ULA...
The cosmological collider physics program aims at probing particle physics at energies as high as the inflationary Hubble scale, $H \le 10^{13}$ GeV, using precision measurements from CMB, large scale structure surveys, and 21-cm cosmology. Heavy particles produced during inflation can impart unique correlations in the density fluctuations across the sky, leading to non-gaussianity (NG) in the...
SPT-3G is the third survey receiver operating on the South Pole Telescope dedicated to high-resolution observations of the cosmic microwave background (CMB). Sensitive measurements of the temperature and polarization anisotropies of the CMB provide a powerful dataset for constraining the fundamental physics of the early universe, including models of inflation and the neutrino sector....
Line-intensity mapping (LIM) of millimeter-wavelength tracers is a promising new technique for mapping cosmic structure at redshifts beyond the reach of galaxy surveys. I will describe the design and science motivation for the South Pole Telescope Summertime Line Intensity Mapper (SPT-SLIM), which seeks to demonstrate the use of on-chip spectrometers based on microwave kinetic inductance...
In the inflationary paradigm, a background of primordial gravitational waves is predicted to be produced. These perturbations would leave a unique signature in the curl component of the cosmic microwave background (CMB) polarization (B-modes). A detection of B-modes spectrum power at degree angular scale would constrain the intensity of the tensor perturbations generated during inflation ....
We present a minimal UV complete framework to embed inflation and dark matter by extending the standard model with a singlet real scalar field (the inflaton) and a singlet fermonic field acting as dark matter. The inflaton features the most general renormalizable polynomial up to quartic order, which is flat due to the existence of a perturbed inflection-point, comfortably fitting CMB...
Axion couplings to photons could induce photon-axion conversion in the presence of magnetic fields in the Universe. This conversion could impact various cosmic distance measurements, such as luminosity distances to type Ia supernovae and angular distances to galaxy clusters, in different ways. In this paper we consider different combinations of the most up-to-date distance measurements to...
Self-interaction among the neutrinos in the early Universe has been proposed as a solution to the Hubble tension, a discrepancy between the measured values of the Hubble constant from CMB and low-redshift data. However, flavor-universal neutrino self-interaction is highly constrained by BBN and several laboratory experiments such as, tau and K-meson decay, double-neutrino beta decay etc. In...
The existence of feebly interacting massive particles (FIMPs) could have significant implications on the effective number of relativistic species Neff in the early Universe. In this work, we investigate in detail how short-lived FIMPs that can decay into neutrinos affect Neff and highlight the relevant effects that govern its evolution. We show that even if unstable FIMPs inject most of their...
I will discuss the implications of self-interacting dark-sectors with light degrees of freedom and mass thresholds on early universe physics. Such models exhibit a relative increase in the energy density of the dark sector when the temperature crosses a mass threshold. Of special interest are models with mass thresholds below $\mathcal{O}({\rm MeV})$. In this region of parameter space, the...
I will describe how to use the 21-cm line of hydrogen to learn about the nature of dark matter in the early universe. I will begin with an overview of the 21-cm signal during cosmic dawn and reionization, and give a brief update of the 2021 status of both theory and measurements. Then, I will show how to use the depth of the signal as a thermometer to learn about anomalous cooling or heating...
I’ll discuss precision calculations of dark radiation in the form of gravitons coming from Hawking evaporation of spinning primordial black holes (PBHs) in the early Universe. This calculation incorporates a careful treatment of extended spin distributions of a population of PBHs, the PBH reheating temperature, and the number of relativistic degrees of freedom. Results are compared to...
GRAMS (Gamma-Ray and AntiMatter Survey) is a next-generation proposed balloon/satellite mission that will be the first to target both MeV gamma-ray observations and antimatter-based indirect dark matter searches with a LArTPC (Liquid Argon Time Projection Chamber) detector. Astrophysical observations at MeV energies have been poorly explored and long-neglected. With a cost-effective,...
Muon track reconstruction in IceCube lacks a proper treatment of stochastic energy losses and is likely limited because of it.
This talk will detail my attempts to add a muon energy loss prior into the IceCube muon reconstruction algorithm and the current state of energy and directional reconstruction with this method.
Next generation neutrino experiments will push the limits in our understanding of astroparticle physics in the neutrino sector to energies orders of magnitude higher than the current state-of-the-art high-energy neutrino experiment, IceCube. These experiments will use neutrinos to tell us about the most extreme environments in the universe, while simultaneously leveraging these extreme...
