## So Chigusa (KEK) “Detecting Light Boson Dark Matter through Conversion into MagnonDetecting Light Boson Dark Matter through Conversion into Magnon”

Detecting Light Boson Dark Matter through Conversion into MagnonDetecting Light Boson Dark Matter through Conversion into Magnon Abstract: Light boson dark matter such as axion or hidden photon can be resonantly converted into a magnon in a magnetic insulator under the magnetic field, which can be detected experimentally. We provide a quantum mechanical formulation for the magnon event rate and … Read More

## Particle Theory Seminar | Djuna Croon (TRIUMF) “New Physics and the Black Hole Mass Gap “

Abstract: In this talk I will demonstrate the potential of the black hole mass gap to probe new physics. The mass gap, in which no black holes can be formed, is a standard prediction of stellar structure theory. I will show that new physics that couples to the Standard Model can act as an additional source of energy loss in … Read More

## Particle Theory Seminar | Soubhik Kumar (Berkeley): “The High-Quality QCD Axion”

Soubhik Kumar (Berkeley) “The High-Quality QCD Axion” The QCD axion provides an elegant solution to the Strong CP Problem. While the minimal realization is vulnerable to the so-called “Axion Quality Problem”, I will consider a more robust realization in the presence of a mirror sector related to the Standard Model by a (softly broken) Z2 symmetry. Interestingly, the resulting “heavy” … Read More

## Marco Gorghetto (Weizmann): “More Axions from Strings”

The axion solution to the strong CP problem also provides a natural dark matter candidate. If the Peccei-Quinn symmetry has ever been restored after inflation, topological defects of the axion field would have formed and produced relic axions, whose abundance is in principle calculable. We study the contribution to the abundance produced by string defects during the so-called scaling regime. … Read More

## Particle Theory Seminar | Marco Gorghetto (Weizmann): “More Axions from Strings”

The axion solution to the strong CP problem also provides a natural dark matter candidate. If the Peccei-Quinn symmetry has ever been restored after inflation, topological defects of the axion field would have formed and produced relic axions, whose abundance is in principle calculable. We study the contribution to the abundance produced by string defects during the so-called scaling regime. … Read More

## Particle Theory Seminar | Shany Danieli (IAS) : Diffuse Galaxies As Probes for Dark Matter on Small Scales

Low mass galaxies provide an essential testing ground for theoretical predictions of cosmology. Their number densities, structures, and internal dynamics can be extremely insightful for studying dark matter on small scales. Recent advances in telescope instrumentation and detection techniques have opened a new window into identifying and characterizing the population of such low surface brightness galaxies. I will discuss the … Read More

## Particle Theory Seminar | Karsten Jedamzik (U. Montpellier): “Relieving the Hubble tension with primordial magnetic fields”

The standard cosmological model determined from the accurate cosmic microwave background measurements made by the Planck satellite implies a value of the Hubble constant H0 that is 4.2 standard deviations lower than the one determined from Type Ia supernovae. The Planck best fit model also predicts higher values of the matter density fraction Omega_m and clustering amplitude S8 compared to … Read More

## PARTICLE THEORY SEMINAR | Seth Koren (Chicago U.) – UV/IR Mixing and the Hierarchy Problem

The persistence of the hierarchy problem points to a violation of effective field theory expectations. A compelling possibility is that this results from a physical violation of EFT, which may arise from correlations between UV and IR physics—as is broadly demanded by gravity. I will discuss Noncommutative Field Theory as a toy model of UV/IR mixing, where an emergent infrared … Read More

## Particle Theory Seminar | Anson Hook (UMD) : “Relaxing the Higgs mass”

Anson Hook (UMD) “Relaxing the Higgs Mass” Abstract: We present a new approach to the Hierarchy problem utilizing self organized criticality. The Higgs mass is generically large, but when expanded around the minimum of the potential, the Higgs mass is small. This approach is analogous to models of the dilaton where the quartic is large at tree level, but is … Read More

## Particle Theory Seminar | Tobias Binder (IPMU) – Dark matter quantum mechanical effects at finite temperature

Tobias Binder (IPMU) “Dark matter quantum mechanical effects at finite temperature” If WIMPs are realized around the TeV-mass region or above, even the heaviest electroweak force carriers could act as long-range forces, leading to a variety of quantum mechanical effects such as the existence of meta-stable DM bound states. The formation and subsequent decay of the latter further deplete the … Read More