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Related papers: A cosmological bound on $e^+ e^-$ mass difference

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Light scalar fields very naturally appear in modern cosmological models, affecting such parameters of Standard Model as electromagnetic fine structure constant $\alpha$, dimensionless ratios of electron or quark mass to the QCD scale,…

Atomic Physics · Physics 2009-08-18 V. V. Flambaum , E. V. Shuryak

If photons had a small electric charge $Q_\gamma$ their path in the galactic magnetic field would be curved, leading to a time delay between photons of different frequency from a distant source. Cocconi's previous application of this…

High Energy Physics - Phenomenology · Physics 2008-11-26 Georg G. Raffelt

The Standard Model cannot explain the dominance of matter over anti-matter in our universe. This imbalance indicates undiscovered physics that violates combined CP symmetry. Many extensions to the Standard Model seek to explain the…

Our primary task is to demonstrate that the logarithmic nonlinearity in the quantum wave equation can cause the spontaneous symmetry breaking and mass generation phenomena on its own, at least in principle. To achieve this goal, we view the…

High Energy Physics - Phenomenology · Physics 2011-02-23 Konstantin G. Zloshchastiev

In this followup analysis, we update previous constraints on the Transitional Planck Mass (TPM) modified gravity model using the latest version of EFTCAMB and provide new constraints using SPT and Planck anisotropy data along with Planck…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-25 Joshua A Kable , Giampaolo Benevento , Graeme E Addison , Charles L Bennett

We study topologically massive (2+1)-dimensional gravity with a negative cosmological constant. The masses of the linearized curvature excitations about AdS_3 backgrounds are not only shifted from their flat background values but, more…

High Energy Physics - Theory · Physics 2010-04-28 S. Carlip , S. Deser , A. Waldron , D. K. Wise

The hypothetical massive dark photon ($\gamma'$) which has kinetic mixing with the SM photon can decay electromagnetically to $e^+e^-$ pairs if its mass $m$ exceeds $2m_e$ and otherwise into three SM photons. These decays yield cosmological…

High Energy Physics - Phenomenology · Physics 2014-11-21 Demos Kazanas , Rabindra N. Mohapatra , Shmuel Nussinov , Vigdor L. Teplitz , Yongchao Zhang

Although cosmic microwave background (CMB) is the most powerful cosmological probe of neutrino masses, it is in trouble with local direct measurements of $H_0$, which is called the $H_0$ tension. Since neutrino masses are correlated with…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-28 Toyokazu Sekiguchi , Tomo Takahashi

We present cosmological bounds on the thermal axion mass in an extended cosmological scenario in which the primordial power spectrum of scalar perturbations differs from the usual power-law shape predicted by the simplest inflationary…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-10 Eleonora Di Valentino , Stefano Gariazzo , Elena Giusarma , Olga Mena

An interesting test of Einstein's equivalence principle (EEP) relies on the observed lag in arrival times of photons emitted from extragalactic transient sources. Attributing the lag between photons of different energies to the…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-20 Adi Nusser

We use the isotropy of the Cosmic Microwave Background to place stringent constraints on a possible electrical charge asymmetry of the universe. We find the excess charge per baryon to be $q_{e-p}<10^{-26}e$ in the case of a uniform…

High Energy Physics - Phenomenology · Physics 2009-06-12 C. Caprini , P. G. Ferreira

While it is established that the effect of neutrinos on the evolution of cosmic structure is small, the upper limits derived from large-scale structure could help significantly to constrain the absolute scale of the neutrino masses. Current…

Astrophysics · Physics 2008-11-26 Ofer Lahav , Oystein Elgaroy

The CPT theorem originally proven by L\"uders and Pauli ensures the equality of masses, lifetimes, magnetic moments and cross sections of any particle and its antiparticle. We show that in a Lorentz invariant quantum field theory described…

High Energy Physics - Theory · Physics 2024-02-09 Luis Álvarez-Gaumé , Moshe M. Chaichian , Markku A. Oksanen , Anca Tureanu

The work shows that the associated Einstein like gravity for the Klein-Gordon field shows the spontaneous emergence of the cosmological pressure tensor density (CPTD) that in the classical limit leads to the cosmological constant (CC). Even…

General Physics · Physics 2020-07-07 Piero Chiarelli

Starting from astrophysical indications that the fine structure constant might undergo a small cosmological time shift, we discuss the implications of such an effect from the point of view of particle physics. Grand unification implies…

High Energy Physics - Phenomenology · Physics 2011-09-13 Xavier Calmet , Harald Fritzsch

We discuss how entropy bounds, which are not respected in the standard cosmology, constrain the parameters of a previously suggested cosmology with a finite total mass. In that alternative cosmology the matter density was postulated to be a…

General Relativity and Quantum Cosmology · Physics 2016-02-09 L. Clavelli

We study CMB constraints on a model with a cosmological constant and a fraction of dark matter non-minimally coupled to a massless scalar field. In this scenario, there is an extra gravity-like fifth force which can affect the evolution of…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-09 Sophie C. F. Morris , Anne M. Green

There has been recent interest in the cosmological consequences of energy-momentum-powered gravity models, in which the matter side of Einstein's equations includes a term proportional to some power, $n$, of the energy-momentum tensor, in…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-03 C. J. A. P. Martins , A. M. M. Vieira

In the presence of Lorentz violation, the Cerenkov-like process $\gamma\rightarrow\gamma+\pi^{0}$ may become allowed for sufficiently energetic photons. Photons above the threshold would lose energy rapidly through pion emission. The fact…

High Energy Physics - Phenomenology · Physics 2016-05-06 Brett Altschul

We study variation of the proton-to-electron mass ratio $ \mu=m_{p}/m_{e} $ by incorporating standard model (SM) of particle physics into an extended Brans-Dicke theory. We show that the evolution of the Higgs vacuum expectation value…

General Relativity and Quantum Cosmology · Physics 2019-11-13 Ahmad Mohamadnejad