Dark energy, scalar singlet dark matter and the Higgs portal

Abstract

One of the simplest extensions of the Standard Model (SM) comprises the inclusion of a massive real scalar field, neutral under the SM gauge groups, to be a dark matter candidate. The addition of a dimension-six term into the potential of the scalar dark matter enables the appearance of a false vacuum that describes the cosmic acceleration. We show that the running of the singlet self-interaction and the Higgs portal coupling differs from the standard scalar singlet dark matter model. If we maintain a positive quartic coupling, it is also possible to describe the accelerated expansion of the Universe through a false vacuum with the addition of a dimension-eight interaction term. In this case, where the potential remains bounded from below at low energies, the false vacuum decay is highly suppressed.

Fractional dark energy: Phantom behavior and negative absolute temperature

“…The simplest candidate for DE is a cosmological constant, agreeing with cosmological observations [3], however, the lack of well-motivated explanations for the origin of such a constant leads to alternative candidates for DE. Among a plethora of options, there are scalar and vector fields [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23], metastable DE [24][25][26][27][28][29][30][31][32], holographic DE [33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49], interacting DE , models using extra dimensions [76], etc.…”

Fractional dark energy

“…However, the observed value of the vacuum energy (10 −47 GeV 4 ) is extremely much smaller than any estimate of the zero-point energy of all modes of a field up to a cutoff scale [3]. The lack of a good explanation for the origin of Λ and its smallness leads to the search of alternative candidates, such as scalar or vector fields [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22], metastable DE [23][24][25][26][27][28][29][30][31], holographic DE [32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48], interacting DE , usage of extra dimensions [74], among others.…”

A note on interacting holographic dark energy with a Hubble-scale cutoff

“…The lack of understating about the nature of the cosmological constant and the aforementioned issues encourage alternative models of DE. Among the many candidates there are scalar and vector fields [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28], metastable DE [29][30][31][32][33][34][35][36][37], models using extra dimensions [38], alternative fluids [39,40], etc. Another explanation for DE comes from the holographic principle, the so-called holographic DE (HDE) [41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57]…”