6,379 research outputs found
Constraining Superluminal Electron and Neutrino Velocities using the 2010 Crab Nebula Flare and the IceCube PeV Neutrino Events
The observation of two PeV-scale neutrino events reported by Ice Cube can, in
principle, allows one to place constraints on Lorentz invariance violation
(LIV) in the neutrino sector. After first arguing that at least one of the
IceCube events was of extragalactic origin, I derive an upper limit for {\it
the difference} between putative superluminal neutrino and electron velocities
of in units where , confirming that the
observed PeV neutrinos could have reached Earth from extragalactic sources. I
further derive a new constraint on the superluminal electron velocity, obtained
from the observation of synchrotron radiation in the Crab Nebula flare of
September, 2010. The inference that the 1 GeV -rays from
synchrotron emission in the flare were produced by electrons of energy up to
PeV indicates the non-occurrence of vacuum \'{C}erenkov radiation by
these electrons. This implies a new, strong constraint on superluminal electron
velocities . It immediately follows that
one then obtains an upper limit on the superluminal neutrino velocity {\it
alone} of , many orders of magnitude
better than the time-of-flight constraint from the SN1987A neutrino burst.
However, if the electrons are {\it subluminal} the constraint on , obtained from the Crab Nebula -ray
spectrum, places a weaker constraint on superluminal neutrino velocity of
.Comment: Expanded and clarified the discussion of the case for extragalactic
origin of the observed neutrinos adding more reference
Micropsephodes bahamaensis, a new species of Anamorphinae (Coleoptera: Cucujoidea: Endomychidae) from the Bahamas, with a key to the New World genera of Anamorphinae
A new species of anamorphine endomychid, Micropsephodes bahamaensis Shockley is described from a small series of 3 specimens collected on North Andros Island in the Bahamas. Besides being the only species known from the Bahamas, M. bahamaensis is readily recognizable from its congeners based on its much larger size, more elongate habitus and features of the galeae and maxillary palpomere IV. Keys to the known species of Micropsephodes and to the adults of the genera of Anamorphinae that occur in the Western Hemisphere are provided
Testing Lorentz Symmetry using High Energy Astrophysics Observations
We discuss some of the tests of Lorentz symmetry made possible by
astrophysical observations of ultrahigh energy cosmic rays, gamma-rays, and
neutrinos. These are among the most sensitive tests of Lorentz symmetry
violation because they are the highest energy phenomena known to man.Comment: revised to match the published paper. Three new references added.
arXiv admin note: substantial text overlap with arXiv:1705.08485,
arXiv:1411.588
Search for the Footprints of New Physics with Laboratory and Cosmic Neutrinos
Observations of high energy neutrinos, both in the laboratory and from cosmic
sources, can be a useful probe in searching for new physics. Such observations
can provide sensitive tests of Lorentz invariance violation (LIV), which may be
a the result of quantum gravity physics (QG). We review some observationally
testable consequences of LIV using effective field theory (EFT) formalism. To
do this, one can postulate the existence of additional small LIV terms in free
particle Lagrangians, suppressed by powers of the Planck mass. The
observational consequences of such terms are then examined. In particular, one
can place limits on a class of non-renormalizable, mass dimension five and six
Lorentz invariance violating operators that may be the result of QG.Comment: Version of a review article in Modern Physics Letters A with eq. (11)
corrected post-publication. arXiv admin note: substantial text overlap with
arXiv:1411.588
Discolomopsis dominicana : a new genus and species of Endomychidae (Coleoptera) from Dominican amber
Discolomopsis, a new genus of Endomychidae (Coleoptera: Cucujoidea), is described and illustrated based on a fossil endomychid embedded in amber resin from the Dominican Republic. Discolomopsis dominicana sp. nov. is designated as the type species for the genus
Tests of Lorentz Invariance Using High Energy Astrophysics Observations
High-energy astrophysics observations provide the best possibilities to
detect a very small violation of Lorentz invariance, such as may be related to
the structure of space-time near the Planck scale. I discuss the possible
signatures of Lorentz invariance violation that can be manifested by observing
the spectra, polarization, and timing of gamma-rays from active galactic nuclei
and gamma-ray bursts. Other sensitive tests are provided by observations of the
spectra of ultrahigh-energy cosmic rays and very high-energy neutrinos. I also
discuss a new time-of-flight analysis of observations of GRB 090510 by the
Fermi gamma-ray Space Telescope. These results, based on high-energy
astrophysical observations, have fundamental implications for space-time
physics and quantum gravity models.Comment: Plenary Talk, Proceedngs of the Sixth Meeting on CPT and Lorentz
Symmetry (CPT'13
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