Conveners
Parallel 3B - Axions
- Christopher ECKNER
Parallel 3B - Axions
- Anastasia Sokolenko
A large flux of axion-like particles can be produced in the solar core. While the majority of these particles will have high velocities and escape the Sun’s gravitational pull, a small fraction of low-velocity particles will become trapped on bound orbits. Over time, an appreciable density of slow-moving axions can accumulate in this “solar basin.” Their subsequent decay to two photons...
Axion-photon conversion is a prime mechanism to detect axion-like particles that share a coupling to the photon. We point out that in the vicinity of neutron stars with strong magnetic fields, magnetars, the effective photon mass receives comparable but opposite contributions from free electrons and the radiation field. This leads to an energy-dependent resonance condition for conversion that...
The electromagnetic interactions of axions can be dramatically enhanced in the magnetospheres of neutron stars as a result of the large magnetic fields and the dilute plasma. In this talk I will discuss the various processes which can give rise to distinct signatures of axions in these environments; this includes: (1) the resonant transition of axion dark matter to nearly monochromatic radio...
Neutron stars can host strong electromagnetic fields deep in their magnetospheres capable of sourcing axions. Low mass axions are produced relativistically and can resonantly convert into radio photons as they escape the magnetosphere. For heavier axions an increasing fraction will instead end up populating a cloud of bound states around the parent neutron star. In this talk I will discuss the...
In this talk, I will discuss a novel electromagnetic signal for two well-motivated ultralight dark-matter (DM) candidates: dark photons and axion-like particles (ALPs). The signal is a small (but larger than expected) oscillating magnetic-field pattern that appears across the entire surface of the Earth, driven by the DM field. It is highly phase-coherent and has a frequency set by the DM...
Axion-like particles (ALPs) are a broad class of pseudo-scalar bosons that generically arise from broken symmetries in extensions of the standard model. In many scenarios, ALPs can mix with photons in regions with high magnetic fields. Photons from distant sources can mix with ALPs, which then travel unattenuated through the Universe, before they mix back to photons in the Milky Way galactic...
Axions and axion-like-particles (ALPs) are well motivated beyond the standard model particles that can explain a variety of unsolved problems in physics, such as the strong CP problem and the nature of dark matter. These particles are characterised by their two-photon coupling, which leads to so-called photon-ALP oscillation as photons propagate through an external magnetic field. Such...
Experimental refinements and technical innovations in the field of extensive air shower telescopes have enabled measurements of Galactic cosmic-ray interactions in the sub-PeV (100 TeV to 1 PeV) range, providing new avenues for the search for new physics and dark matter. For the first time, we exploit sub-PeV (10 TeV -- 1 PeV) observations of Galactic diffuse gamma rays by Tibet AS$\gamma$ and...
Future cosmological probes promise significant progress in probing the dark universe and the related fundamental particles. Their impact is most powerful when we combine cosmological data with astrophysical observations and laboratory experiments. While computational tools are available for such studies, the large number of model parameters and ensuring consistency between data sets can...
Although the presence of oscillations in fuzzy dark matter (FDM) cores has been noted previously [1-3], e.g. effects of core oscillations on the structure and dynamics of galaxies [2,3], and limits on the constituent boson mass [1], some open questions remain.
Here, we investigate the dynamics and properties of FDM core oscillations both in the absence and presence of self-interactions. We...
