Solutions to axion electromagnetodynamics and new search strategies of sub-μeV axion

Abstract

The Witten effect implies the electromagnetic interactions between axions and magnetic monopoles, and the quantum electromagnetodynamics (QEMD) properly describes interactions of electric charges, magnetic charges and photons. Based on the QEMD, a generic low-energy axion-photon effective field theory was built by introducing two four-potentials (Aμ and Bμ) to describe a photon. More anomalous axion-photon interactions and couplings (gaAA, gaBB and gaAB) arise in contrary to the ordinary axion coupling $$ {g}_{a\gamma \gamma}{a F}^{\mu \nu}{\overset{\sim }{F}}_{\mu \nu} $$ g aγγ aF μν F ~ μν . As a consequence, the conventional axion Maxwell equations are further modified. We properly solve the new axion-modified Maxwell equations and obtain the axion-induced electromagnetic fields given a static electric or magnetic field. It turns out that the dominant couplings gaAB and gaBB can be probed in the presence of external magnetic field and electric field, respectively. The induced oscillating magnetic fields are always suppressed compared with the electric fields for the axions with large Compton wavelengths. This is contrary to the situation in conventional experiments searching for the oscillating magnetic fields induced by sub-μeV axions. Thus, we propose new strategies to measure the new couplings for sub-μeV axion in haloscope experiments.

Quantum calculation of axion-photon transition in electromagnetodynamics for cavity haloscope*

“…. Note that the result of this quantum calculation under the assumption of is larger than the classical result of the conventional axion cavity haloscope [24,46] by a factor of . We presume…”

“…When and , the occupation number for thermal photons is quite low and the cavity can be treated as a single photon emitter. Although the usual electromagnetic power radiated in the cavity is calculated in classical field theory [24], the actual description is a quantum mechanical process of axion to photon conversion, as stated by P. Sikivie in Ref. [37].…”

“…This is in contrast to the conventional axion EFT in the quantum electrodynamics (QED) framework. As a result of the above generic axion-photon Lagrangian, the conventional axion Maxwell equations [24] are further modified and based on this some new detection strategies for axions have been studied in recent years [25−28].…”

Alena Tensor and Its Possible Applications in Unification Theories

“…Alena Tensor also introduces the possibility of a new interpretation of the forces attributed to Dark Matter. Apart from the interpretation presented in section 2.1 in which the force associated with Dark Matter is the Abraham-Lorentz effect, it may also prove helpful for analysis of Maxwell's equations with axion modifications [34] and attempts to explain Dark Matter based on these particles [35], especially in the context of the results regarding Sigma-8 tension [36].…”

Non-standard axion electrodynamics and the dual Witten effect

“…The fact that axion electrodynamics breaks electric-magnetic duality has spurred some authors to propose non-standard formulations of axion electrodynamics, which aim to either restore electric-magnetic duality [13] or break it in alternative ways [14][15][16]. These non-standard formulations of axion electrodynamics not only allow for g aγγ ∝ 1/e 2 , implying much stronger couplings, they also introduce new terms in (1.3); for example, allowing E ∂a ∂t to source ∇ × E. Some of the proposed modifications have begun to receive attention in the context of the design or interpretation of experiments [17][18][19][20][21][22][23][24][25][26][27][28] or astrophysical observations [29]. Thus, it is important to understand to what extent such a non-standard axion electrodynamics is theoretically and phenomenologically viable.…”