Dimming supernovae without cosmic acceleration.

Theory Division T-8, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Physical Review Letters (Impact Factor: 7.73). 05/2002; 88(16):161302. DOI: 10.1103/PhysRevLett.88.161302
Source: arXiv

ABSTRACT We present a simple model where photons propagating in extragalactic magnetic fields can oscillate into very light axions. The oscillations may convert some of the photons, departing a distant supernova, into axions, making the supernova appear dimmer and hence more distant than it really is. Averaging over different configurations of the magnetic field we find that the dimming saturates at about one-third of the light from the supernovae at very large redshifts. This results in a luminosity distance versus redshift curve almost indistinguishable from that produced by the accelerating Universe, if the axion mass and coupling scale are m approximately 10(-16) eV, M approximately 4 x 10(11) GeV. This phenomenon may be an alternative to the accelerating Universe for explaining supernova observations.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The paper under review presents a simple higher dimensional FRW-type of model where the acceleration is apparently caused by the presence of the extra dimensions. More precisely, a scenario is examined where the accelerated expansion of the universe at the current epoch may be made possible without forcing ourselves to invoke any time dependent extraneous scalar field or vacuum energy. By taking a five-dimensional spatially flat, homogeneous space-time with perfect fluid as matter field and assuming a specific form of the deceleration parameter, the authors show that the universe decelerates at the early era and after a certain instant, it starts accelerating in conformity with the present day observations. Correspondence to Wesson’s induced matter theory is also briefly discussed.
    International Journal of Modern Physics A 08/2006; · 1.09 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We revise the bound from the supernova SN1987A on the coupling of ultralight axion-like particles (ALPs) to photons. In a core-collapse supernova, ALPs would be emitted via the Primakoff process, and eventually convert into gamma rays in the magnetic field of the Milky Way. The lack of a gamma-ray signal in the GRS instrument of the SMM satellite in coincidence with the observation of the neutrinos emitted from SN1987A therefore provides a strong bound on their coupling to photons. Due to the large uncertainty associated with the current bound, we revise this argument, based on state-of-the-art physical inputs both for the supernova models and for the Milky-Way magnetic field. Furthermore, we provide major amendments, such as the consistent treatment of nucleon-degeneracy effects and of the reduction of the nuclear masses in the hot and dense nuclear medium of the supernova. With these improvements, we obtain a new upper limit on the photon-ALP coupling: g_{a\gamma} < 5.3 x 10^{-12} GeV^{-1}, for m_a < 4.4 x 10^{-10} eV, and we also give its dependence at larger ALP masses. Moreover, we discuss how much the Fermi-LAT satellite experiment could improve this bound, should a close-enough supernova explode in the near future.
    Journal of Cosmology and Astroparticle Physics 02/2015; 2015(02):006. · 6.04 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Gamma-rays from cosmological sources contain information about gamma-ray interactions. Standard model and non-standard model photon interactions along the path between the source and the observer can lead to changes in the energy or state of the photons, which in turn alters the observed energy spectrum of the source. In general, these interactions are a function of photon energy as well as source distance. Here we show how existing high energy gamma-ray observations of blazars can be used to constrain the coupling of axion-like-particles (ALPs) to the photon. The same ALP-photon coupling that has been invoked to explain the observations of TeV blazars beyond their pair production horizon is shown to have a potential effect on the data set of Fermi blazars.
    Journal of Cosmology and Astroparticle Physics 08/2014; 2014(08):021. · 5.88 Impact Factor

Full-text (2 Sources)

Available from
Jun 4, 2014