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Sub-GeV dark matter candidates are of increasing interest, because long-favored candidates such as GeV-scale WIMPs have not been detected. For low-mass dark matter, model-independent constraints are weak or nonexistent. We show that for…

高能物理 - 唯象学 · 物理学 2019-07-09 Christopher V. Cappiello , Kenny C. Y. Ng , John F. Beacom

We show that a mass-varying neutrino model driven by scalar field dark energy relaxes the existing upper bound on the current neutrino mass to ${\sum m_\nu < 0.72}$ eV. We extend the standard $\Lambda$ cold dark matter model by introducing…

宇宙学与河外天体物理 · 物理学 2024-04-16 Vitor da Fonseca , Tiago Barreiro , Nelson J. Nunes

We point out a new and largely model-independent constraint on the dark matter scattering cross section with nucleons, applying when this quantity is larger than for typical weakly interacting dark matter candidates. When the dark matter…

天体物理学 · 物理学 2008-11-26 Gregory D. Mack , John F. Beacom , Gianfranco Bertone

We investigate the impact of neutrino emission via Hawking radiation from primordial black holes (PBHs) on the cosmological effective number of neutrino species, $N_{\mathrm{eff}}$, after neutrino decoupling. By comparing this effect with…

宇宙学与河外天体物理 · 物理学 2025-09-03 Héctor Sanchis , Gabriela Barenboim , Yuber F. Perez-Gonzalez

Recent observations constrain the amount of Dark Radiation ($\Delta N_{\rm eff}$) and may even hint towards a non-zero value of $\Delta N_{\rm eff}$. It is by now well-known that this puts stringent constraints on the sequestered Large…

高能物理 - 唯象学 · 物理学 2014-10-01 Arthur Hebecker , Patrick Mangat , Fabrizio Rompineve , Lukas T. Witkowski

We investigate the way how the total mass sum of neutrinos can be constrained from the neutrinoless double beta decay and cosmological probes with cosmic microwave background (WMAP 3-year results), large scale structures including 2dFGRS…

高能物理 - 唯象学 · 物理学 2010-12-13 Yong-Yeon Keum , Kiyotomo Ichiki , Taka Kajino

This year's Physics Nobel prize for the discovery of neutrino oscillations which resolved the problem of the missing solar neutrinos and the atmospheric muon neutrinos implies that at least one of the three neutrino species has a tiny mass.…

综合物理 · 物理学 2016-04-26 C Sivaram , Kenath Arun , Kiren O

A lower bound on the light neutrino mass $m_\nu$ is derived in the framework of a geometrical interpretation of quantum mechanics. Using this model and the time of flight delay data for neutrinos coming from SN1987A, we find that the…

广义相对论与量子宇宙学 · 物理学 2009-11-11 G. Lambiase , G. Papini , R. Punzi , G. Scarpetta

In their recent paper, Chan and Lee discuss an interesting possibility: radio continuum emission from a dwarf irregular galaxy may be used to constrain upper limits on the cross section of annihilating dark matter. They claim that the…

星系天体物理 · 物理学 2021-03-17 Volker Heesen , Marcus Brüggen

We study a dark energy model composed of a bare negative cosmological constant and a single ultra-light axion, motivated by the string axiverse. Assuming that intelligent observers arise and observe, as in our universe, the onset of…

高能物理 - 唯象学 · 物理学 2025-12-02 Kai Murai , Fuminobu Takahashi

We study direct detection bounds on cosmic ray-upscattered dark matter in simplified models including light mediators. We find that the energy dependence in the scattering cross section is significant, and produces stronger bounds than…

高能物理 - 唯象学 · 物理学 2020-07-01 James B. Dent , Bhaskar Dutta , Jayden L. Newstead , Ian M. Shoemaker

One of the major goals of future Cosmic Microwave Background measurements is the accurate determination of the effective number of neutrinos $N_{\rm eff}$. Reaching an experimental sensitivity of $\Delta N_{\rm eff} = 0.013$ could indeed…

宇宙学与河外天体物理 · 物理学 2018-03-28 Ludovico Capparelli , Eleonora Di Valentino , Alessandro Melchiorri , Jens Chluba

Dark matter annihilation into charged particles is necessarily accompanied by gamma rays, produced via radiative corrections. Internal bremsstrahlung from the final state particles can produce hard gamma rays up to the dark matter mass,…

天体物理学 · 物理学 2010-02-01 Nicole F. Bell , Thomas D. Jacques

By using most of the present CMB and LSS measurements and the BBN constraints on the primordial helium abundance, Y_p, we set bounds on the radiation content of the Universe and neutrino properties. We consider lepton asymmetric…

天体物理学 · 物理学 2010-02-26 Lucia Aurelia Popa , Ana Vasile

A period of early matter domination can give rise to the correct dark matter abundance for a broad range of dark matter annihilation rate $\langle \sigma_{\rm ann} v \rangle_{\rm f}$. Here, we examine this scenario for situations where…

宇宙学与河外天体物理 · 物理学 2018-10-29 Rouzbeh Allahverdi , Koushik Dutta , Anshuman Maharana

Axions and dark photons are common in many extensions of the Standard Model. The dark axion portal -- an axion coupling to the dark photon and photon -- can significantly modify their phenomenology. We study the cosmological constraints on…

高能物理 - 唯象学 · 物理学 2024-04-01 Heejoung Hong , Ui Min , Minho Son , Tevong You

A lower bound on $\Delta m^{2}$ for atmospheric neutrino oscillations can be obtained from the global value of $R$ at a given energy. This bound may be more reliable than one based on the observed isotropy. Some global values of $R$ imply…

高能物理 - 唯象学 · 物理学 2007-05-23 J. M. LoSecco

A host of dark energy models and non-standard cosmologies predict an enhanced Hubble rate in the early Universe: perfectly viable models, which satisfy Big Bang Nucleosynthesis (BBN), cosmic microwave background and general relativity…

高能物理 - 唯象学 · 物理学 2009-11-11 M. Schelke , R. Catena , N. Fornengo , A. Masiero , M. Pietroni

The theoretical interpretation of dark matter (DM) experiments is hindered by uncertainties on the dark matter density and velocity distribution inside the Solar System. In order to quantify those uncertainties, we present a parameter that…

高能物理 - 唯象学 · 物理学 2018-12-14 Alejandro Ibarra , Bradley J. Kavanagh , Andreas Rappelt

Under the assumption that some part of the observed highest energy cosmic rays consists of protons originating from cosmological distances, we derive bounds on the associated flux of neutrinos generated by inelastic processes with the…

高能物理 - 唯象学 · 物理学 2009-11-10 Z. Fodor , S. D. Katz , A. Ringwald , H. Tu