42 pages Revtex4. This version contains corrections and changes contained in the published version, Rev. Mod. Phys. 82, 939-979 (2010), with a few additions
Efforts to place limits on deviations from canonical formulations of electromagnetism and gravity have probed length scales increasing dramatically over time.Historically, these studies have passed through three stages: (1) Testing the power in the inverse-square laws of Newton and Coulomb, (2) Seeking a nonzero value for the rest mass of photon or graviton, (3) Considering more degrees of freedom, allowing mass while preserving explicit gauge or general-coordinate invariance. Since our previous review the lower limit on the photon Compton wavelength has improved by four orders of magnitude, to about one astronomical unit, and rapid current progress in astronomy makes further advance likely. For gravity there have been vigorous debates about even the concept of graviton rest mass. Meanwhile there are striking observations of astronomical motions that do not fit Einstein gravity with visible sources. "Cold dark matter" (slow, invisible classical particles) fits well at large scales. "Modified Newtonian dynamics" provides the best phenomenology at galactic scales. Satisfying this phenomenology is a requirement if dark matter, perhaps as invisible classical fields, could be correct here too. "Dark energy" {\it might} be explained by a graviton-mass-like effect, with associated Compton wavelength comparable to the radius of the visible universe. We summarize significant mass limits in a table.
It is well known that gravitons can convert into photons, and vice versa, in the presence of cosmological magnetic fields. We study this conversion process in the context of atomic dark matter scenario. In this scenario, we can expect cosmological dark magnetic fields, which are free from the stringent constraint from the cosmic microwave observations. We find that gravitons can effectively convert into dark photons in the presence of cosmological dark magnetic fields. The graviton-dark photon conversion effect may open up a new window for ultra high frequency gravitational waves.
In this work I study the effect of graviton-photon mixing in a constant external magnetic field and find for the first time in the literature exact solution of the equations of motion. In particular, I apply the effect of graviton-photon mixing to the case of interaction of gravitational waves with an external magnetic field and calculate the intensity Stokes parameter of the produced electromagnetic radiation. The obtained results are new and extend previous results obtained by using approximation methods.
Photon-graviton conversion in a magnetic field is a process that is usually studied at tree level, but the one-loop corrections due to scalars and spinors have also been calculated. Differently from the tree-level process, at one-loop one finds the amplitude to depend on the photon polarization, leading to dichroism. However, previous calculations overlooked a tadpole contribution of the type that was considered to be vanishing in QED for decades but erroneously so, as shown by H. Gies and one of the authors in 2016. Here we compute this missing diagram in closed form, and show that it does no…
It has long been known that photons and gravitons may appear as vector and tensor Goldstone modes caused \ by spontaneous Lorentz invariance violation (SLIV). Usually this approach is considered for photons and gravitons separately. We develop the emergent electrogravity theory consisting of the ordinary QED and the tensor field gravity model which mimics the linearized general relativity in Minkowski spacetime. In this theory, Lorentz symmetry appears incorporated into higher global symmetries of the length-fixing constraints put on the vector and tensor fields involved, $A_{μ}^{2}=\pm M_{A}^…
One loop photon-graviton mixing in an electromagnetic field: Part 3
Helmholtz-Zentrum Dresden-Rossendorf（德累斯顿罗森多夫赫尔姆霍兹中心）；Dipartimento di Fisica ed Astronomia, Università di Bologna（博洛尼亚大学物理与天文系）；INFN, Sezione di Bologna（意大利国家核物理研究所博洛尼部分所）；Helmholtz-Institut Jena（耶拿赫尔姆霍兹研究所）；Theoretisch-Physikalisches Institut, Friedrich-Schiller-Universität Jena（耶拿弗里德里希·席勒大学理论物理研究所）；Facultad de Ciencias Físico-Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo（圣尼古拉斯伊达尔戈米却肯大学物理数学科学学院）
Absorption of Gravitons and Photon Luminosities of Interstellar/Intergalactic Hydrogen Atoms
Institute of Nuclear and Particle Physics, NCSR ”Demokritos”（德谟克利特国家科学研究中心核与粒子物理研究所）；School of Physics and Astronomy, Sun Yat-Sen University（中山大学物理学院）；School of Science, Quantum Optoelectronics Lab, Westlake University（西湖大学理学院）
We study the space of all kinematically allowed four photon and four graviton S-matrices, polynomial in scattering momenta. We demonstrate that this space is the permutation invariant sector of a module over the ring of polynomials of the Mandelstam invariants $s$, $t$ and $u$. We construct these modules for every value of the spacetime dimension $D$, and so explicitly count and parameterize the most general four photon and four graviton S-matrix at any given derivative order. We also explicitly list the local Lagrangians that give rise to these S-matrices. We then conjecture that the Regge gr…
We explore a novel process in the early Universe in which thermalized photons are converted into gravitons in the presence of strong primordial magnetic fields. It is found that the frequency of generated gravitational waves (GWs) is typically of order of GHz and their amplitude can be up to $ Ω_\mathrm{GW}h^2 \sim 10^{-10}$. If detected with future developments of the technology to explore this frequency region, the produced stochastic GW background enables us to know when and how strong the primordial magnetic fields are generated. From the peak frequency of the GWs, we can also probe the nu…
The interactions of gravitons with spin-1 matter are calculated in parallel with the well known photon case. It is shown that graviton scattering amplitudes can be factorized into a product of familiar electromagnetic forms, and cross sections for various reactions are straightforwardly evaluated using helicity methods. Universality relations are identified. Extrapolation to zero mass yields scattering amplitudes for photon-graviton and graviton-graviton scattering. The phenomenon of light bending near a massive object, which is generally treated using classical general relativity, is discusse…
We consider the Kaluza-Klein (KK) graviton and its decays in the presence of the light radion, the modulus of extra dimension, appearing naturally light due to classical scale invariance in warped gravity. Due to the presence of a sizable wavefunction overlap in the extra dimension between the KK graviton and the radion, the KK graviton can decay largely into a pair of radions, each of which decays into a pair of collimated photons or photon-jets. Focusing on the setup where the KK graviton has suppressed couplings to the Higgs boson and fermions, we discuss the bounds on the light radion in t…
Now, it is already not a big surprise that due to the spontaneous Lorentz invariance violation (SLIV) there may emerge massless vector and tensor Goldstone modes identified particularly with photon and graviton. Point is, however, that this mechanism is usually considered separately for photon and graviton, though in reality they appear in fact together. In this connection, we recently develop the common emergent electrogravity model which would like to present here. This model incorporates the ordinary QED and tensor field gravity mimicking linearized general relativity. The SLIV is induced b…
In this paper, we explore Bell inequality violation for $2\rightarrow2$ scattering in Effective Field Theories (EFTs) of photons, gluons, and gravitons. Using the CGLMP Bell parameter ($I_2$), we show that, starting from an appropriate initial non-product state, the Bell inequality can always be violated in the final state (i.e.,$I_2 >2$) at least for some scattering angle. For an initial product state, we demonstrate that abelian gauge theories behave qualitatively differently than non-abelian gauge theories (or Gravity) from the point of view of Bell violation in the final state: in the non-…
After the recent historical discovery of gravitational wave, it is curious to speculate upon the detection prospect of the quantum graviton in the terrestrial accelerator-based experiment. We carefully investigate the "golden" channels, $J/ψ(Υ)\toγ+\text{graviton}$, which can be pursued at \textsf{BESIII} and \textsf{Belle 2} experiments, by searching for single-photon plus missing energy events. Within the effective field theory (EFT) framework of General Relativity (GR) together with Nonrelativistic QCD (NRQCD), we are capable of making solid predictions for the corresponding decay rates. It…
We have investigated real graviton emission in the ADD and RS model of extra dimensions through the photoproduction process pp-> p gamma p-> pGqX at the LHC. We have considered all contributions from the subprocesses gamma q -> G q, where q=u,d,c,s,b,anti-u,anti-d, anti-c, anti-s, anti-b quark. The constraints on model parameters of the ADD and RS model of extra dimensions have been calculated. During numerical calculations we have taken account of 3, 4, 5 and 6 large extra dimensional scenarios. The constraints on RS model parameters have been calculated by considering G -> gamma gamma, e^- e…
The vacuum polarization in an external gravitational field due to one loop electron-positron pair and one loop millicharged fermion-antifermion pair is studied. Considering the propagation of electromagnetic (EM) radiation and gravitational waves (GWs) in an expanding universe, it is shown that by taking into account QED effects in curved spacetime, the propagation velocity of photons is superluminal and can exceed that of gravitons. We apply these results to the case of the GW170817 event detected by LIGO. If the EM radiation and GWs are emitted either simultaneously or with a time difference…
Graduate Institute for Advanced Studies, SOKENDAI（SOKENDAI高级研究研究生院）；National Astronomical Observatory of Japan（日本国立天文台）；Department of Physics, Kobe University（神户大学物理学系）；Department of Astronomy, The University of Tokyo（东京大学天文学系）；Theory Center, IPNS, KEK（KEK高能加速器研究机构IPNS理论中心）；Kavli IPMU (WPI), UTIAS, The University of Tokyo（东京大学UTIAS卡弗里宇宙物理起源研究所(WPI)）；Department of Physics, Institute of Science Tokyo（东京科学大学物理学系）
In the sixties Ogievetskii and Polubarinov proposed the concept of a notoph, whose helicity properties are complementary to those of a photon. Later, Kalb and Ramond (and others) developed this theoretical concept. And, at the present times it is widely accepted. We analyze the quantum theory of antisymmetric tensor fields with taking into account mass dimensions of notoph and photon. It appears to be possible to describe both photon and notoph degrees of freedom on the basis of the modified Bargmann-Wigner formalism for the symmetric second-rank spinor. Next, we proceed to derive equations fo…
We present the NLO QCD corrections to the production of a photon pair in association with one jet, where the photons are stemming from graviton decay, within models of large extra dimensions. Our results for the loop amplitudes are produced with the program GOSAM for automated one-loop calculations. We show distributions for several observables for 4, 5 and 6 extra dimensions and demonstrate that the differential K-factors are far from being uniform.
In warped 5D models of hierarchy and flavor, the first Kaluza-Klein (KK) state of the graviton $G_1$ is heavy enough to decay into a photon and its first KK mode $γ_1$ on-shell: $G_1 \to γ_1 γ$. The volume-suppression of the rate for this process [relative to 2-body decay into heavy Standard Model (SM) final states ($W/Z/t/H$)] may be partially compensated by the simplicity of the photon final state. We consider $γ_1 \to W^+W^-$, with a typical O(1) branching fraction, and focus on the semi-leptonic final state $W(\to jj) W(\to \ell, ν)$ with $\ell=e,μ$. The SM background originates from $2\to…
