ELKO fermions as dark matter candidates

Abstract

We study the implications of the ELKO fermions as a cold dark matter candidate. Such fermions arise in theories that are not symmetric under the full Lorentz group. Although they do not carry electric charge, ELKOs can still couple to photons through a nonstandard interaction. They also couple to the Higgs but do not couple to other standard model particles. We impose limits on their coupling strength and the ELKO mass assuming that these particles give dominant contribution to the cosmological cold dark matter. We also determine limits imposed by the direct dark matter search experiments on the ELKO-photon and the ELKO-Higgs coupling. Furthermore we determine the limit imposed by the gamma ray bursts time delay observations on the ELKO-Higgs coupling. We find that astrophysical and cosmological considerations rule out the possibility that ELKO may contribute significantly as a cold dark matter candidate. The only allowed scenario in which it can contribute significantly as a dark matter candidate is that it was never in equilibrium with the cosmic plasma. We also obtain a relationship between the ELKO self-coupling and its mass by demanding it to be consistent with observations of dense cores in the galactic centers.

The Theory of Local Mass Dimension One Fermions of Spin One Half

“…In view of the results on locality and Lorentz covariance reported here it is important to revisit the analysis and claims of [101] and also those calculations that use full apparatus of the theory of quantum fields, and not merely Elko. In the same thread, given the interest in mass dimension one fermions a number of S-matrix calculations were done and published [102][103][104][105][106][107]. These need to be revisited also.…”

Mass-dimension-one fermions and their gravitational interaction

“…[3]. These formulations boosted several works in a broad range of areas, for instance mathematical physics [4][5][6][7][8][9][10], phenomenology of particles [11][12][13][14][15][16] and cosmology [17][18][19][20][21][22][23][24][25][26][27][28][29][30].…”

Evading Weinberg's no-go theorem to construct mass dimension one fermions: Constructing darkness

“…118 (2017) no.6, 60001 DOI: 10.1209/0295-5075/118/60001 Why do dark matter and dark energy [1][2][3][4][5][6] have extremely limited interaction with the particles of the standard model of high energy physics? What type of quantum field theoretic formalism describes them [7][8][9][10][11][12][13][14][15]? The defining feature of the dark sector is its 'darkness' (that is, its limited or no interactions with the standard model field).…”