102 research outputs found
Antimatter from Microscopic Black Holes
The spectrum of positrons and antiprotons produced by the outflow of high
temperature matter surrounding microscopic black holes is calculated for
energies between five GeV and the Planck energy. The results may be applicable
for the last few hours and minutes of a microscopic black hole's lifetime.Comment: 7 pages, 3 figure
The Highly Damped Quasinormal Modes of Extremal Reissner-Nordstr\"om and Reissner-Nordstr\"om-de Sitter Black Holes
We analyze in detail the highly damped quasinormal modes of -dimensional
extremal Reissner-Nordstrm and
Reissner-Nordstrm-de Sitter black holes. We only consider the
extremal case where the event horizon and the Cauchy inner horizon coincide. We
show that, even though the topology of the Stokes/anti-Stokes lines in the
extremal case is different than the non-extremal case, the highly damped
quasinormal mode frequencies of extremal black holes match exactly with the
extremal limit of the non-extremal black hole quasinormal mode frequencies.Comment: 17 pages, 5 figure
A Modified Stern-Gerlach Experiment Using a Quantum Two-State Magnetic Field
The Stern-Gerlach experiment has played an important role in our
understanding of quantum behavior. We propose and analyze a modified version of
this experiment where the magnetic field of the detector is in a quantum
superposition, which may be experimentally realized using a superconducting
flux qubit. We show that if incident spin- particles couple with the
two-state magnetic field, a discrete target distribution results that resembles
the distribution in the classical Stern-Gerlach experiment. As an application
of the general result, we compute the distribution for a square waveform of the
incident fermion. This experimental setup allows us to establish: (1) the
quantization of the intrinsic angular momentum of a spin- particle, and
(2) a correlation between EPR pairs leading to nonlocality, without necessarily
collapsing the particle's spin wavefunction.Comment: 12 pages, 2 figure
The Mystery of the Asymptotic Quasinormal Modes of Gauss-Bonnet Black Holes
We analyze the quasinormal modes of -dimensional Schwarzschild black holes
with the Gauss-Bonnet correction in the large damping limit and show that
standard analytic techniques cannot be applied in a straightforward manner to
the case of infinite damping. However, by using a combination of analytic and
numeric techniques we are able to calculate the quasinormal mode frequencies in
a range where the damping is large but finite. We show that for this damping
region the famous appears in the real part of the quasinormal mode
frequency. In our calculations, the Gauss-Bonnet coupling, , is taken
to be much smaller than the parameter , which is related to the black hole
mass.Comment: 12 pages and 5 figure
Survey of intestinal parasites of Neogobius bathybius in south-western coasts of the Caspian Sea
Neogobius bathybious fish were caught in south-western coastal waters of the Caspian Sea, from Anzali to Zibakenar, by bottom trawl. Fish specimens numbering 97 were examined for intestinal parasites and prevalence, intensity and dominance were calculated for each kind of parasites. Four different parasites were isolated from the fish including Dichelyne minutes which with %85.56 prevalence and %65.76 intensity was the most important infecting parasite. Corynosoma strumosum showed %51.54, Anisakis sp. %12.37 and Eustrogylides excises %1.03 prevalence as the other isolated parasites in fish
Universality of Highly Damped Quasinormal Modes for Single Horizon Black Holes
It has been suggested that the highly damped quasinormal modes of black holes
provide information about the microscopic quantum gravitational states
underlying black hole entropy. This interpretation requires the form of the
highly damped quasinormal mode frequency to be universally of the form:
, where is an integer, and is the
black hole temperature. We summarize the results of an analysis of the highly
damped quasinormal modes for a large class of single horizon, asymptotically
flat black holes.Comment: 9 pages, 1 figure, submitted to the proceedings of Theory CANADA 1,
which will be published in a special edition of the Canadian Journal of
Physic
The first record of Pomphorhynchus laevis (Acanthocephala) in chub, Squalius cephalus (Linnaeus, 1758) from Gamasiab River, Hamedan, Iran
Pomphorhynchus laevis is a common fish parasite in Europe which has been reported from Acipenser stellatus, Barbus capito, Barbus lacerta, Barbus mursa and Onchorhynchus mykiss in Iran. In a survey on the aquaculture potential of Gamasiab River in Hamedan Province, endemic fish parasites were investigated in summer and autumn 2008. After recording biometric characteristics, common necropsy and parasitology methods were used. Live acanthocephalans were relaxed in distilled water at 4 ºC for 1 h and fixed in 10% hot buffered formalin. All specimens fixed in 10% formalin were stained with aqueous acetocarmine, dehydrated and mounted in Permount. The worms were identified using parasite identification keys. A total of 36 individuals of Chub, Squalius cephalus, were investigated and 459 individuals of Pomphorhinchus laevis were recovered from intestine of 32 fish specimens. The prevalence mean intensity and mean abundance of P. laevis were %88.9, 14.3 and 12.7, respectively. The maximum number of the parasite recorded in a five years old fish (403gr in weight) was 130 plerocercoids. Chub, Squalius cephalus, is reported for the first time as a new host record for P. laevis in Iran
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