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warm dark matter and the Formation of First Galaxies

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Journal of Modern Physics 2022年第6期13卷 932-948页

作者： Bruce Hoeneisen Universidad San Francisco de Quito Quito Ecuador

By numerical integration of hydro-dynamical equations, we study the formation of elliptical and spiral galaxies starting from primordial linear density-velocity-gravitational perturbations. Both dark matter and baryons are included. warm dark matter perturbations acquire two low mass cut-offs: the free-streaming cut-off due to the power spectrum free-streaming cut-off factor τ2(k), and the velocity dispersion cut-off. The Press-Schechter mass distribution does not include velocity dispersion, and should not be used below the velocity dispersion cut-off mass. From the formation of first galaxies and reionization, we estimate limits on the non-relativistic warm dark matter velocity dispersion at expansion parameter , with .

关键词： warm dark matter First Galaxies First Stars Population III Stars Reioniza-tion

A Study of Three Galaxy Types, Galaxy Formation, and warm dark matter

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International Journal of Astronomy and Astrophysics 2021年第4期11卷 489-508页

作者： Bruce Hoeneisen Universidad San Francisco de Quito Quito Ecuador

We try to bridge the gap between the theory of linear density-velocity-gravitational perturbations in the early universe, and the relaxed galaxies we observe today. We succeed quantitatively for dark matter if dark matter is warm. The density runs of baryons and of dark matter of relaxed galaxies are well described by hydro-static equations. The evolution from initial linear perturbations to final relaxed galaxies is well described by hydro-dynamical equations. These equations necessarily include dark matter velocity dispersion. If the initial perturbation is large enough, the halo becomes self-gravitating. The adiabatic compression of the dark matter core determines the final core density, and provides a negative stabilizing feedback. The relaxed galaxy halo may form adiabatically if dark matter is warm. The galaxy halo radius continues to increase indefinitely, so has an ill-defined mass.

关键词： Galaxy Formation warm dark matter Adiabatic Invariant of warm dark matter

Understanding the Formation of Galaxies with warm dark matter

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Journal of Modern Physics 2023年第S1期14卷 1741-1754页

作者： Bruce Hoeneisen Universidad San Francisco de Quito Quito Ecuador

The formation of galaxies with warm dark matter is approximately adiabatic. The cold dark matter limit is singular and requires relaxation. In these lecture notes, we develop, step-by-step, the physics of galaxies with warm dark matter, and their formation. The theory is validated with observed spiral galaxy rotation curves. These observations constrain the properties of the dark matter particles.

关键词： warm dark matter Galaxy Galaxy Formation

Exploring Inflation Options for warm dark matter Coupled to the Higgs Boson

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International Journal of Astronomy and Astrophysics 2023年第3期13卷 217-235页

作者： Bruce Hoeneisen Universidad San Francisco de Quito Quito Ecuador

We extend the Standard Model with a scalar warm dark matter field S with an interaction with the Higgs boson ∅. This warm dark matter scenario is in agreement with cosmological observations if S and ∅ come into thermal and diffusive equilibrium before the temperature drops below the Higgs boson mass mH. We study inflation driven by the fields ∅ or S, and also study preheating and reheating, in order to constrain the parameters of this extension of the Standard Model. It is remarkable that, with the current data, these models pass a closure test with no free parameters.

关键词： warm dark matter Inflation Preheating Reheating

Cold or warm dark matter?: A Study of Galaxy Stellar Mass Distributions

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International Journal of Astronomy and Astrophysics 2020年第2期10卷 57-70页

作者： Bruce Hoeneisen Universidad San Francisco de Quito Quito Ecuador

We compare the observed galaxy stellar mass distributions in the redshift range with expectations of the cold ΛCDM and warm ΛWDM dark matter models, and obtain the warm dark matter cut-off wavenumber: . This result is in agreement with the independent measurements with spiral galaxy rotation curves, confirms that kfs is due to warm dark matter free-streaming, and is consistent with the scenario of dark matter with no freeze-in and no freeze-out. Detailed properties of warm dark matter can be derived from kfs. The data disfavors the ΛCDM model.

关键词： dark matter warm dark matter dark matter Properties Galaxy Stellar Mass

Comments on warm dark matter Measurements and Limits

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International Journal of Astronomy and Astrophysics 2022年第1期12卷 94-109页

作者： Bruce Hoeneisen Universidad San Francisco de Quito Quito Ecuador

Observed spiral galaxy rotation curves allow a measurement of the warm dark matter particle velocity dispersion and mass. The measured thermal relic mass mh ≈100 eV is in disagreement with limits, typically in the range 1 to 4 keV. We review the measurements, update the no freeze-in and no freeze-out scenario of warm dark matter, and try to identify the cause of the discrepancies between measurements and limits.

关键词： warm dark matter Spiral Galaxy Rotation Curves Stellar Mass Distributions Lyman-α Forest

Measurements of the dark matter Mass, Temperature and Spin

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International Journal of Astronomy and Astrophysics 2024年第3期14卷 184-202页

作者： Bruce Hoeneisen Universidad San Francisco de Quito Quito Ecuador

We summarize several measurements of the dark matter temperature-to-mass ratio, or equivalently, of the comoving root-mean-square thermal velocity of warm dark matter particles vhrms(1). The most reliable determination of this parameter comes from well measured rotation curves of dwarf galaxies by the LITTLE THINGS collaboration: vhrms(1)=406±69 m/s. Complementary and consistent measurements are obtained from rotation curves of spiral galaxies measured by the SPARC collaboration, density runs of giant elliptical galaxies, galaxy ultra-violet luminosity distributions, galaxy stellar mass distributions, first galaxies, and reionization. Having measured vhrms(1), we then embark on a journey to the past that leads to a consistent set of measured dark matter properties, including mass, temperature and spin.

关键词： warm dark matter Dwarf Galaxies Spiral Galaxies Elliptical Galaxies Galaxy Distributions First Galaxies Reionization

NANOGrav results and dark first order phase transitions

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Science China(Physics,Mechanics & Astronomy) 2021年第9期64卷 9-14页

作者： Andrea Addazi Yi-Fu Cai Qingyu Gan Antonino Marciano Kaiqiang Zeng Center for Theoretical Physics College of PhysicsSichuan UniversityChengdu 610065China Istituto Nazionale di Fisica Nucleare sezione Roma Tor VergataRome I-00133Italy Department of Astronomy School of Physical SciencesUniversity of Science and Technology of ChinaHefei 230026China Chinese Academy of Sciences Key Laboratory for Researches in Galaxies and CosmologyUniversity of Science and Technology of ChinaHefei 230026China School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China Department of Physics&Center for Field Theory and Particle Physics Fudan UniversityShanghai 200433China Laboratori Nazionali di Frascati Istituto Nazionale di Fisica Nucleare Via Enrico Fermi 54Frascati(Roma)I-00044Italy

The recent NANOGrav evidence of a common-source stochastic background provides a hint to gravitational waves(GW)radiation from the Early *** show that this result can be interpreted as a GW spectrum produced from first order phase transitions(FOPTs)around a temperature in the keV-MeV *** a class of FOPTs at temperatures much below the electroweak scale can be naturally envisaged in several warm dark matter models such as Majoron dark matter.

关键词： gravitational waves first order phase transitions warm dark matter effective field theory

Measurement of the dark matter Velocity Dispersion with Dwarf Galaxy Rotation Curves

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International Journal of Astronomy and Astrophysics 2022年第4期12卷 363-381页

作者： Bruce Hoeneisen Universidad San Francisco de Quito Quito Ecuador

warm dark matter has, by definition, a velocity dispersion. Let vhms(a)=vhms(1)/a be the root-mean-square velocity of non-relativistic warm dark matter particles in the early universe at expansion parameter a. vhms(1) is an adiabatic invariant. We obtain vhms(1) in the core of 11 dwarf galaxies dominated by dark matter, from their observed rotation curves, up to a rotation and relaxation correction. We obtain a mean 0.490 km/s and standard deviation 0.160 km/s, with a distribution peaked at the lower end. We apply a mild, data driven, rotation and relaxation correction that obtains the adiabatic invariant in the core of the galaxies: vhms(1)=0.406 ±0.069 km/s. These two small relative standard deviations justify the prediction that the adiabatic invariant vhms(1) in the core of the galaxies is of cosmological origin if dark matter is warm. This result is in agreement with measurements of vhms(1) based on spiral galaxy rotation curves, galaxy ultra-violet luminosity distributions, galaxy stellar mass distributions, the formation of first galaxies, reionization, and the velocity dispersion cut-off mass.

关键词： warm dark matter Galaxy Rotation Curves Dwarf Galaxies