Equation of state, universal profiles, scaling and macroscopic quantum effects in warm dark matter galaxies

Vega, H. J. de; Sánchez, Norma G.

doi:10.1140/epjc/s10052-017-4645-8

Cited by 19 publications

(91 citation statements)

References 52 publications

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“…This corresponds to Model II of Sec. IX C. 51 The gaseous solution (G) is always thermodynamically stable. The core-halo solution (CH) is thermodynamically stable for M h < (M h ) MCP and unstable for M h > (M h ) MCP (as explained before, we consider the thermodynamical stability in the microcanoncal ensemble).…”

Section: A Assumptionsmentioning

confidence: 99%

Predictive model of BEC dark matter halos with a solitonic core and an isothermal atmosphere

Chavanis

2019

Phys. Rev. D

121

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We develop a model of Bose-Einstein condensate dark matter halos with a solitonic core and an isothermal atmosphere based on a generalized Gross-Pitaevskii-Poisson equation [P.H. Chavanis, Eur. Phys. J. Plus 132, 248 (2017)]. This equation provides a heuristic coarse-grained parametrization of the ordinary Gross-Pitaevskii-Poisson equation accounting for violent relaxation and gravitational cooling. It involves a cubic nonlinearity taking into account the self-interaction of the bosons, a logarithmic nonlinearity associated with an effective temperature, and a source of dissipation. It leads to superfluid dark matter halos with a core-halo structure. The quantum potential or the self-interaction of the bosons generates a solitonic core that solves the cusp problem of the cold dark matter model. The logarithmic nonlinearity generates an isothermal atmosphere accounting for the flat rotation curves of the galaxies. The dissipation ensures that the system relaxes towards an equilibrium configuration. In the Thomas-Fermi approximation, the dark matter halo is equivalent to a barotropic gas with an equation of state P = 2πas 2 ρ 2 /m 3 + ρkBT /m, where as is the scattering length of the bosons and m is their individual mass. We numerically solve the equation of hydrostatic equilibrium and determine the corresponding density profiles and rotation curves. We impose that the surface density of the halos has the universal value Σ0 = ρ0r h = 141 M /pc 2 obtained from the observations. For a boson with ratio as/m 3 = 3.28 × 10 3 fm/(eV/c 2 ) 3 , we find a minimum halo mass (M h )min = 1.86 × 10 8 M and a minimum halo radius (r h )min = 788 pc. This ultracompact halo corresponds to a pure soliton which is the ground state of the Gross-Pitaevskii-Poisson equation. For (M h )min < M h < (M h ) * = 3.30 × 10 9 M the soliton is surrounded by a tenuous isothermal atmosphere without plateau. For M h > (M h ) * we find two branches of solutions corresponding to (i) pure isothermal halos without soliton and (ii) isothermal halos harboring a central soliton and presenting a plateau. The purely isothermal halos (gaseous phase) are stable. For M h > (M h )c = 6.86 × 10 10 M , they are indistinguishable from the observational Burkert profile. For (M h ) * < M h < (M h )c, the deviation from the isothermal law (most probable state) may be explained by incomplete violent relaxation, tidal effects, or stochastic forcing. The isothermal halos harboring a central soliton (core-halo phase) are canonically unstable (having a negative specific heat) but they are microcanonically stable so they are long-lived. By extremizing the free energy (or entropy) with respect to the core mass, we find that the core mass scales as Mc/(M h )min = 0.626 (M h /(M h )min) 1/2 ln(M h /(M h )min). For a halo of mass M h = 10 12 M , similar to the mass of the halo that surrounds our Galaxy, the solitonic core has a mass Mc = 6.39×10 10 M and a radius Rc = 1 kpc. The solitonic core cannot mimic by itself a supermassive black hole at the center of the Galaxy but i...

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Section: A Assumptionsmentioning

confidence: 99%

Predictive model of BEC dark matter halos with a solitonic core and an isothermal atmosphere

Chavanis

2019

Phys. Rev. D

121

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“…The Burkert profile well represents the family of the cored halo distributions: noticeably, inside r 0 , cannot be discriminated from the other cored profiles including the "theoretical" ones occurring in the cases of degenerate fermionic particles or boson condensates (see Appendices A1 and A2 in [95]), [67,87,91,94]. Of course, despite that the circular velocity fits can be very similar independently of the assumed (cored) profile, the resulting 3D relationship: central density-core radius-halo mass is instead very density profile dependent.…”

Section: The Dm Halomentioning

confidence: 98%

“…In fact, for masses of about ∼keV, the particle de-Broglie scale length is of the order ∼tens kpc, i.e., of the order of the stellar disk size in spirals. Thus, a quantum pressure emerges ( [86][87][88][89][90][91][92]) that shapes the inner DM density profile forming a cored distribution that [86,93] have well reproduced with the pseudo-isothermal profile:…”

Section: Sterile Neutrino: Warm Dark Matter Particlementioning

confidence: 99%

“…Thus, this relationship extends over 18 blue magnitudes over objects spanning from dwarf to giant galaxies ( [160,[241][242][243][244][245][246]) and very different morphology. It is difficult to not consider Equation (12) as a primary consequence of the dark particle properties, e.g., as it emerges in the case of a ∼2 keV neutrino ( [91,94]).…”

Section: Lsbs Structure Scaling Lawsmentioning

confidence: 99%

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Fundamental Properties of the Dark and the Luminous Matter from the Low Surface Brightness Discs

Salucci

Paolo

2021

Universe

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Dark matter (DM) is one of the biggest mystery in the Universe. In this review, we start reporting the evidences for this elusive component and discussing about the proposed particle candidates and scenarios for such phenomenon. Then, we focus on recent results obtained for rotating disc galaxies, in particular for low surface brightness (LSB) galaxies. The main observational properties related to the baryonic matter in LSBs, investigated over the last decades, are briefly recalled. Next, these galaxies are analyzed by means of the mass modelling of their rotation curves both individual and stacked. The latter analysis, via the universal rotation curve (URC) method, results really powerful in giving a global or universal description of the properties of these objects. We report the presence in LSBs of scaling relations among their structural properties that result comparable with those found in galaxies of different morphologies. All this confirms, in disc systems, the existence of a strong entanglement between the luminous matter (LM) and the dark matter (DM). Moreover, we report how in LSBs the tight relationship between their radial gravitational accelerations g and their baryonic components gb results to depend also on the stellar disk length scale and the radius at which the two accelerations have been measured. LSB galaxies strongly challenge the ΛCDM scenario with the relative collisionless dark particle and, alongside with the non-detection of the latter, contribute to guide us towards a new scenario for the DM phenomenon.

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“…In particular, warm dark matter consisting of 2-7 keV sterile neutrinos has a different contribution to the CνB anisotropies as compared to cold dark matter. Cold dark matter is assumed to have exactly zero pressure at high redshift while warm dark matter carries some degree of non-zero radiation pressure according to its mass [3,4].…”

Section: Introductionmentioning

confidence: 99%

Impact of Warm Dark Matter on the Cosmic Neutrino Background Anisotropies

Tully

Zhang

2022

Universe

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The Cosmic Neutrino Background (CνB) anisotropies for massive neutrinos are a unique probe of large-scale structure formation. The redshift-distance measure is completely different for massive neutrinos as compared to electromagnetic radiation. The CνB anisotropies in massive neutrinos grow in response to non-relativistic motion in gravitational potentials seeded by relatively high k-modes. Differences in the early phases of large-scale structure formation in warm dark matter (WDM) versus cold dark matter (CDM) cosmologies have an impact on the magnitude of the CνB anisotropies for contributions to the angular power spectrum that peak at high k-modes. We take the examples of WDM consisting of 2, 3, or 7 keV sterile neutrinos and show that the CνB anisotropies for 0.05 eV neutrinos drop off at high-l multipole moment in the angular power spectrum relative to CDM. At the same angular scales that one can observe baryonic acoustical oscillations in the CMB, the CνB anisotropies begin to become sensitive to differences in WDM and CDM cosmologies. The precision measurement of high-l multipoles in the CνB neutrino sky map is a potential possibility for the PTOLEMY experiment with thin film targets of spin-polarized atomic tritium superfluid that exhibit significant quantum liquid amplification for non-relativistic relic neutrino capture.

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Equation of state, universal profiles, scaling and macroscopic quantum effects in warm dark matter galaxies

Cited by 19 publications

References 52 publications

Predictive model of BEC dark matter halos with a solitonic core and an isothermal atmosphere

Predictive model of BEC dark matter halos with a solitonic core and an isothermal atmosphere

Fundamental Properties of the Dark and the Luminous Matter from the Low Surface Brightness Discs

Impact of Warm Dark Matter on the Cosmic Neutrino Background Anisotropies

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