PIKIMO Spring 2024

Session

Talks

4 May 2024, 09:35

Room 151 (Loomis Laboratory of Physics)

Conveners

Talks: Morning Session 1

• Christina Gao

Talks: Morning Session 2

• Wen Han Chiu (UIUC)

Talks: Afternoon Session 1

• Shashin Pavaskar

Talks: Afternoon Session 2

• Avery Tishue (UIUC)

2. Detecting Axion Dark Matter with Black Hole Polarimetry

Xucheng Gan

04/05/2024, 09:35

The axion, as a leading dark matter candidate, is the target of many on-going and proposed experimental searches based on its coupling to photons. Ultralight axions that couple to photons can also cause polarization rotation of light which can be probed by cosmic microwave background. In this work, we show that a large axion field is inevitably developed around black holes due to the...

6. Statistics of axion wind detection with superfluid Helium-3

Aarav Mande

04/05/2024, 09:55

The homogeneous precession domain (HPD) of superfluid $^{3}$He has recently been identified as a detection medium which might provide sensitivity to the axion-nucleon coupling $g_{aNN}$ competitive with, or surpassing, existing experimental proposals. In this work, we make a detailed study of the statistical and dynamical properties of the HPD system in order to make realistic projections for...

3. Visible Axinovae: Axion Star Explosions with Photon Emissions

Huangyu Xiao (Fermilab)

04/05/2024, 10:35

Axion dark matter or any ultralight bosonic dark matter can go through Bose-Einstein condensation due to the large phase density, leading to the formation of axion stars or solitons in the halo center. The formation rate is further enhanced in the presence of substructures such axion miniclusters which are expected in the post-inflationary scenario of the QCD axion or axion-like particles....

1. Generalized Global Symmetries and Nonperturbative Quantum Flavodynamics

Seth Koren (University of Notre Dame)

04/05/2024, 10:55

Generalized global symmetries are present in theories of particle physics, and understanding their structure can give insight into these theories and UV completions thereof. We will identify non-invertible chiral symmetries in certain flavorful Z' extensions of the Standard Model, and this will lead us to interesting nonperturbative effects in theories of gauged non-Abelian flavor. For the...

9. Amplifying CMB phase shift with dark matter-radiation interactions

Daven Wei Ren Ho

04/05/2024, 11:15

The peaks of the CMB spectra provide a direct cosmological probe for studying dark sector physics. Specifically, a shift in the peak positions corresponds to a phase shift in the acoustic oscillations of the photon-baryon plasma before recombination, which is sensitive to the propagation behavior of non-photon radiation. It has been established that CMB spectra shift to higher l-modes if the...

8. Multi-electron muon decays

Tony Menzo

04/05/2024, 13:55

We study the exotic muon decays with five charged tracks in the final state. First, we investigate the Standard Model rate for $\mu \rightarrow eeeee \nu \nu$ and find that the Mu3e experiment should have tens to hundreds of signal events per $10^{15}$ $\mu^+$ decays, depending on the signal selection strategy. We then turn to a neutrinoless $\mu \rightarrow eeeee$ decay that may arise in...

5. Large Blue Spectral Index From a Conformal Limit of a Rotating Complex Scalar

SAI CHAITANYA TADEPALLI

04/05/2024, 14:15

One well known method of generating a large blue spectral index for axionic isocurvature perturbations is through a flat direction not having a quartic potential term for the radial partner of the axion field. In this work, we show how one can obtain a large blue spectral index even with a quartic potential term associated with the Peccei-Quinn symmetry breaking radial partner. We use the fact...

10. Topological aspects of particle production in the early universe

Ms Nidhi Sudhir (University of Wisconin-Madison)

04/05/2024, 14:35

We study topological aspects of particle production using Stokes phenomenon. An explicit map between the standard $\beta$-coefficient computation, and Stokes constants from the perspective of the F-matrix formalism is presented. In scenarios where the particle dispersion relation reduces in the long wavelength limit ($k\rightarrow 0$) to the form $z^n$ $(n\in \mathbb{Z}_{>0})$ in complexified...

7. A tale of tails via QCD insights

Alex Edison (Northwestern University)

04/05/2024, 16:10

The first observation of gravitational waves nearly ten years ago has ushered us into the age of gravitational wave astrophysics. With an eye towards the precision of future detectors, improving theoretical understanding of gravitational wave dynamics is a necessity. In this talk, I will discuss my work on importing methods and insights from particle physics into the study of a piece of the...

11. Seeing highly anisotropic gravitational wave backgrounds from the early universe

Arushi Bodas (University of Chicago and Fermilab)

04/05/2024, 16:30

A stochastic gravitational wave background (GWB) produced in the early universe would necessarily exhibit anisotropies analogous to the CMB. In multi-field inflationary scenarios, anisotropies in GWB could differ significantly from those of the CMB if sourced by a quantum field different from the one sourcing CMB. In these scenarios, however, the more interesting case of highly anisotropic GWB...

4. Crescendo Beyond the Horizon: More Gravitational Waves from Domain Walls Bounded by Inflated Cosmic Strings

Yunjia Bao (University of Chicago)

04/05/2024, 16:50

Gravitational-wave (GW) signals offer unique probes into the early universe dynamics, particularly those from topological defects. We investigate a scenario involving a two-step phase transition resulting in a network of domain walls bound by cosmic strings. By introducing a period of inflation between the two phase transitions, we show that the stochastic GW signal can be greatly enhanced....