3,953 research outputs found
Kunsia tomentosus (Rodentia: Cricetidae)
Kunsia tomentosus (Lichtenstein, 1830), the woolly giant rat, is a semifossorial cricetid typically associated with the Cerrado and Beni domains in central South America. Kunsia was recently revised and includes only 1 species. It is the largest extant sigmondontine and is readily distinguishable by its size, a body covered with dark-gray fur that is coarse and dense, moderately short tail, short limbs, bicolored manus and pes, and long, powerful claws. It inhabits primarily open grasslands and savannas from central and southwestern Brazil and northern Bolivia. K. tomentosus presently is not considered threatened; however, westernmost populations have presumably been extirpated in the past 2 centuries.Fil: Bezerra, Alexandra M. R.. Universidade do BrasÃlia; Brasil. Escola Nacional de Saude Publica Sergio Arouca. Fundación Oswaldo Cruz; BrasilFil: Pardiñas, Ulises Francisco J.. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; Argentin
Relativistic Landau Levels in the Rotating Cosmic String Spacetime
In the spacetime induced by a rotating cosmic string we compute the energy
levels of a massive spinless particle coupled covariantly to a homogeneous
magnetic field parallel to the string. Afterwards, we consider the addition of
a scalar potential with a Coulomb-type and a linear confining term and
completely solve the Klein-Gordon equations for each configuration. Finally,
assuming rigid-wall boundary conditions, we find the Landau levels when the
linear defect is itself magnetized. Remarkably, our analysis reveals that the
Landau quantization occurs even in the absence of gauge fields provided the
string is endowed with spin.Comment: Writing and grammar revised. References added. 14 pages, no figures.
To appear in European Phys. J.
Reply to "Comment on 'Gravitating Magnetic Monopole in the Global Monopole Spacetime' "
In this Reply I present some arguments in favor of the stability of the
topological defect composed by global and magnetic monopoles.Comment: 1 page, no figures. Revised version improves the theoretical analysis
about electrostatic self-interaction in the global monopole spacetim
On Effective Spacetime Dimension in the Ho\v{r}ava-Lifshitz Gravity
In this manuscript we explicitly compute the effective dimension of spacetime
in some backgrounds of Ho\v{r}ava-Lifshitz (H-L) gravity. For all the cases
considered, the results are compatible with a dimensional reduction of the
spacetime to , at high energies (ultraviolet limit), which is confirmed
by other quantum gravity approaches, as well as to , at low energies
(infrared limit). This is obtained by computing the free energy of massless
scalar and gauge fields. We find that the only effect of the background is to
change the proportionality constant between the internal energy and
temperature. Firstly, we consider both the non-perturbative and perturbative
models involving the matter action, without gravitational sources but with
manifest time and space symmetry breaking, in order to calculate modifications
in the Stephan-Boltzmann law. When gravity is taken into account, we assume a
scenario in which there is a spherical source with mass and radius in
thermal equilibrium with radiation, and consider the static and spherically
symmetric solution of the H-L theory found by Kehagias-Sfetsos (K-S), in the
weak and strong field approximations. As byproducts, for the weak field regime,
we used the current uncertainty of the solar radiance measurements to establish
a constraint on the free parameter of the K-S solution. We also
calculate the corrections, due to gravity, to the recently predicted attractive
force that black bodies exert on nearby neutral atoms and molecules.Comment: references adde
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