002742573 001__ 2742573
002742573 005__ 20201025041155.0
002742573 0248_ $$aoai:cds.cern.ch:2742573$$pcerncds:FULLTEXT$$pcerncds:CERN:FULLTEXT$$pcerncds:CERN
002742573 037__ $$9arXiv$$aarXiv:2010.03383$$castro-ph.CO
002742573 035__ $$9arXiv$$aoai:arXiv.org:2010.03383
002742573 035__ $$9Inspire$$aoai:inspirehep.net:1821799$$d2020-10-24T04:21:28Z$$h2020-10-25T03:00:09Z$$mmarcxml$$ttrue$$uhttp://old.inspirehep.net/oai2d
002742573 035__ $$9Inspire$$a1821799
002742573 041__ $$aeng
002742573 100__ $$aRamazanov, Sabir$$uPrague, Inst. Phys.
002742573 245__ $$9arXiv$$aObserving primordial magnetic fields through Dark Matter
002742573 269__ $$c2020-10-16
002742573 300__ $$a30 p
002742573 500__ $$9arXiv$$a29 pages and 4 figures, v2 with updated references
002742573 520__ $$9arXiv$$aPrimordial magnetic fields are often thought to be the early Universe seeds that have bloomed into what we observe today as galactic and extra-galactic magnetic fields. Owing to their minuscule strength, primordial magnetic fields are very hard to detect in cosmological and astrophysical observations. We show how this changes if a part of neutral Dark Matter has a magnetic susceptibility. In this way, by studying Dark Matter one can obtain information about the properties of primordial magnetic fields, even if the latter have a comoving amplitude $B_0 \lesssim0.01~\mbox{nG}$. In our model Dark Matter is a stable singlet scalar $\chi$, which interacts with electromagnetism through the Rayleigh operator as $\chi^2 F_{\mu \nu} F^{\mu \nu}/\Lambda^2$. For primordial magnetic fields present in the early Universe this operator forces the $Z_2$-symmetry of the model to be spontaneously broken. Later, when the primordial magnetic field redshifts below a critical value, the symmetry is restored through an "inverse phase transition". At that point the field $\chi$ begins to oscillate and acts as a "magnetomorphic" Dark Matter component, inheriting the properties of the primordial magnetic field space distribution. In particular, for a nearly flat spectrum of magnetic field fluctuations, the scalar $\chi$ carries a statistically anisotropic isocurvature mode. We discuss the parameter space of the model and consider the possibility that the bulk of the Dark Matter is composed of the same particles $\chi$ produced via the freeze-in mechanism.
002742573 540__ $$3preprint$$aarXiv nonexclusive-distrib 1.0$$uhttp://arxiv.org/licenses/nonexclusive-distrib/1.0/
002742573 65017 $$2arXiv$$ahep-th
002742573 65017 $$2SzGeCERN$$aParticle Physics - Theory
002742573 65017 $$2arXiv$$ahep-ph
002742573 65017 $$2SzGeCERN$$aParticle Physics - Phenomenology
002742573 65017 $$2arXiv$$aastro-ph.CO
002742573 65017 $$2SzGeCERN$$aAstrophysics and Astronomy
002742573 690C_ $$aCERN
002742573 690C_ $$aPREPRINT
002742573 700__ $$aUrban, Federico R.$$iINSPIRE-00199170$$kORCID:0000-0001-9403-767X$$memail:[email protected]$$uPrague, Inst. Phys.
002742573 700__ $$aVikman, Alexander$$iINSPIRE-00045749$$kORCID:0000-0003-3957-2068$$memail:[email protected][email protected]$$uPrague, Inst. Phys.
002742573 8564_ $$82254899$$s555737$$uhttps://cds.cern.ch/record/2742573/files/2010.03383.pdf$$yFulltext
002742573 8564_ $$82254900$$s1595$$uhttps://cds.cern.ch/record/2742573/files/leg.png$$y00001 The exclusion plot shows allowed values (white region) for the mass $M$ of the field $\chi$ and the self-interaction coupling constant $\lambda$. The other parameters, the reheating temperature $T_{reh}$, the DM fraction $f$ defined by Eq.~\eqref{ft}, and the present day magnetic to radiation energy density ratio $r_B (t_0)$ defined by Eq.~\eqref{rB}, are set to the values shown in the plot. The number of ultra-relativistic degrees of freedom is fixed to $g_{*, reh}=g_* (T_*)=10^3$. For values of the mass $M$ and the coupling constant $\lambda$ along the solid orange line, the rest of DM is made of particles $\chi$ produced through the freeze-in mechanism.The exclusion plot shows allowed values (white region) of the DM fraction $f$ defined by Eq.~\eqref{ft} and the present day magnetic to radiation energy density ratio $r_B (t_0)$ defined by Eq.~\eqref{rB}. The other parameters, the reheating temperature $T_{reh}$, the mass $M$ of the field $\chi$, and the self-interaction coupling constant $\lambda$, are set to the values shown in the plot. The number of ultra-relativistic degrees of freedom is fixed to $g_{*, reh}=g_* (T_*)=10^3$. For $f$ and $r_B (t_0)$ taking values along the solid orange line, the rest of DM is made of particles $\chi$ produced through the freeze-in mechanism.
002742573 8564_ $$82254901$$s13431$$uhttps://cds.cern.ch/record/2742573/files/fig2.png$$y00002 The exclusion plot shows allowed values (white region) of the DM fraction $f$ defined by Eq.~\eqref{ft} and the present day magnetic to radiation energy density ratio $r_B (t_0)$ defined by Eq.~\eqref{rB}. The other parameters, the reheating temperature $T_{reh}$, the mass $M$ of the field $\chi$, and the self-interaction coupling constant $\lambda$, are set to the values shown in the plot. The number of ultra-relativistic degrees of freedom is fixed to $g_{*, reh}=g_* (T_*)=10^3$. For $f$ and $r_B (t_0)$ taking values along the solid orange line, the rest of DM is made of particles $\chi$ produced through the freeze-in mechanism.
002742573 8564_ $$82254902$$s23740$$uhttps://cds.cern.ch/record/2742573/files/fig1.png$$y00000 The exclusion plot shows allowed values (white region) for the mass $M$ of the field $\chi$ and the self-interaction coupling constant $\lambda$. The other parameters, the reheating temperature $T_{reh}$, the DM fraction $f$ defined by Eq.~\eqref{ft}, and the present day magnetic to radiation energy density ratio $r_B (t_0)$ defined by Eq.~\eqref{rB}, are set to the values shown in the plot. The number of ultra-relativistic degrees of freedom is fixed to $g_{*, reh}=g_* (T_*)=10^3$. For values of the mass $M$ and the coupling constant $\lambda$ along the solid orange line, the rest of DM is made of particles $\chi$ produced through the freeze-in mechanism.
002742573 960__ $$a11
002742573 980__ $$aPREPRINT