Constraints on ultralight axions from compact binary systems

Probing the angle of birefringence due to long range axion hair from pulsars

“…It has been discussed in [36][37][38] that if axions have coupling with nucleons, then axions are sourced by pulsars like neutron stars or white dwarfs. In the following, we have discussed how pulsars can be the source of long range axion hair.…”

“…The plot of axion field and axion potential inside and outside of a pulsar and the variation of axion charge with axion mass is shown in Fig. 1 [38]. In Fig.…”

“…The sign change in the axion potential from the coupling to gluons at large densities allows axions to be sourced by the neutron stars or pulsars [36][37][38]. The coherent oscillation of the axion potential in free space produces the axionic density.…”

“…As the dipole axis precesses around the spin axis, there is a synchrotron radiation along the magnetic poles that appears as the pulsed signal in a cone swept out by the radio beam. Rotating neutron star or pulsar can also form binaries with other neutron star, white dwarf, and black hole, and there can be ultralight scalar or pseudoscalar axion radiation [36][37][38][39] or vector boson radiation [40] due to orbital period decay. Ultralight vector bosons can also mediate between the Sun and the planets and contribute to the perihelion precession of planets [41].…”

Light dark matter annihilation and scattering in LHC detectors

“…Below this mass scale, wave dark matter leads to the variation of fundamental constants, which can be probed in atomic spectroscopy [15][16][17][18], laser interference [19], Eot-Wash and ULDM-fifth-force experiments [20,21]. Other new strategies include nuclear clocks [22], compact binary systems [23,24] or gravitational wave detectors [25][26][27]. All these measurements probe masses down to 10 −24 eV, below which the de Broglie wavelength is larger than 100 kpc and galaxy-size structures do not form [28].…”