axions

We examine the effective field equations that are obtained from the axi-dilaton gravity action with a second order Euler-Poincare term and a cosmological constant in all higher dimensions. We solve these equations for five-dimensional spacetimes possessing homogeneity and isotropy in their three-dimensional subspaces. For a number of interesting special cases we show that the solutions fall into two main classes: The first class consists of time-dependent solutions with spherical or hyperboloidal symmetry which require certain fine-tuning relations between the coupling constants of the model and the cosmological constant. Solutions in the second class are locally static and prove the validity of Birkhoff's staticity theorem in the axi-dilaton gravity. We also give a special class of static solutions, among them the well-known black hole solutions in which the usual electric charge is superseded by an axion charge.

1 Laboratoire National des Champs Magnétiques Pulsés, CNRS/INSA/UPS, UMR 5147, 31400, Toulouse, France 2 Department of Physics, University of Alberta, 11322-89 Av, Edmonton, AB, Canada 3 Department of Physics, University of Wisconsin, Madison, WI ...

A brief review of light dark matter particles and their spectroscopy is presented, specifically aimed at understanding the interaction mechanisms of axion and Axion-Like Particles (ALPs) with matter and an interim proposal and some ideas for possible detection of these evasive particles. In order to venture into the highly challenging spectral regions and extremely weak signals involved with these searches (especially for the DFSZ axions), a different scheme is proposed departing from the conventional resonant cavity mass scan and heterodyne detection methods. We aim to look for a fixed mass axionic field and concentrate our search at the corresponding resonant frequency and its higher harmonics using a simple phase-sensitive dc detection method, which could possibly be helpful in substantially reducing both the hardware, experiment complexities and long run times. The probable mass range suggested in the model presented here begins with 22.5microeV, corresponding to a resonant freq...

A brief review of light dark matter particles and their spectroscopy is presented, specifically aimed at understanding the interaction mechanisms of axion and Axion-Like Particles (ALP's) with matter and an interim proposal and some ideas for possible detection of these evasive particles. In order to venture into the highly challenging spectral regions and extremely weak signals involved with these searches (especially for the DFSZ axions), a different scheme is proposed departing from the conventional resonant cavity mass scan and heterodyne detection methods. We aim to look for a fixed mass axionic field and concentrate our search at the corresponding resonant frequency and its higher harmonics using a simple phase-sensitive dc detection method, which could possibly be helpful in substantially reducing both the hardware, experiment complexities and long run times. The probable mass range suggested in the model presented here begins with 22.5+0.5eV/c 2 mass value, corresponding to a resonant frequency of 5.4+ 0.12GHz, going all the way to its two multiples of 90 and 112.5+ 0.5eV/c 2 (corresponding to 24.3 and 27.0+ 0.12GHz frequencies, respectively), with high probability of finding an axion/ALP around these mass values, if axions exist and couple to photons. We present a comprehensive measurement strategy and spectroscopy technique based upon this model which revolves around a three-stage amplification and phase-sensitive detection scheme to maximize an axion's resonant coupling to the U(1) fields under a coherent Primakoff effect-like interaction. The feasibility of proposed scheme is demonstrated with some calculations, simulations and preliminary tests. This experimental technique and ideas reported here have significant potential to be developed into an extremely sensitive narrow-range dark matter axion/ALP spectroscopy experiment.