3,454 research outputs found
Additional Comments on the Application of Statistical Analysis to Differential Pass-Fail Rates in Employment Testing
Thermodynamic Properties of Spherically-Symmetric, Uniformly-Accelerated Reference Frames
We aim to study the thermodynamic properties of the spherically symmetric
reference frames with uniform acceleration, including the spherically symmetric
generalization of Rindler reference frame and the new kind of uniformly
accelerated reference frame. We find that, unlike the general studies about the
horizon thermodynamics, one cannot obtain the laws of thermodynamics for their
horizons in the usual approaches, despite that one can formally define an area
entropy (Bekenstein-Hawking entropy). In fact, the common horizon for a set of
uniformly accelerated observers is not always exist, even though the
Hawking-Unruh temperature is still well-defined. This result indicates that the
Hawking-Unruh temperature is only a kinematic effect, to gain the laws of
thermodynamics for the horizon, one needs the help of dynamics. Our result is
in accordance with those from the various studies about the acoustic black
holes.Comment: 8 page
Corrections to the Cardy-Verlinde formula from the generalized uncertainty principle
In this letter, we compute the corrections to the Cardy-Verlinde formula of
dimensional Schwarzschild black hole. These corrections stem from the
generalized uncertainty principle. Then we show, one can taking into account
the generalized uncertainty principle corrections of the Cardy-Verlinde entropy
formula by just redefining the Virasoro operator and the central charge
.Comment: 8 pages, no figure
On Coordinate Transformations in Planar Noncommutative Theories
We consider planar noncommutative theories such that the coordinates verify a
space-dependent commutation relation. We show that, in some special cases, new
coordinates may be introduced that have a constant commutator, and as a
consequence the construction of Field Theory models may be carried out by an
application of the standard Moyal approach in terms of the new coordinates. We
apply these ideas to the concrete example of a noncommutative plane with a
curved interface. We also show how to extend this method to more general
situations.Comment: 20 pages, 1 figure. references adde
Dressing the Giant Magnon II
We extend our earlier work by demonstrating how to construct classical string
solutions describing arbitrary superpositions of scattering and bound states of
dyonic giant magnons on S^5 using the dressing method for the SU(4)/Sp(2) coset
model. We present a particular scattering solution which generalizes solutions
found in hep-th/0607009 and hep-th/0607044 to the case of arbitrary magnon
momenta. We compute the classical time delay for the scattering of two dyonic
magnons carrying angular momenta with arbitrary relative orientation on the
S^5.Comment: 13 pages, harvma
Unruh response functions for scalar fields in de Sitter space
We calculate the response functions of a freely falling Unruh detector in de
Sitter space coupled to scalar fields of different coupling to the curvature,
including the minimally coupled massless case. Although the responses differ
strongly in the infrared as a consequence of the amplification of superhorizon
modes, the energy levels of the detector are thermally populated.Comment: 16 pages, 1 figure, accepted for publication by Classical and Quantum
Gravit
Divergence Cancellation and Loop Corrections in String Field Theory on a Plane Wave Background
We investigate the one-loop energy shift E to certain two-impurity string
states in light-cone string field theory on a plane wave background. We find
that there exist logarithmic divergences in the sums over intermediate mode
numbers which cancel between the cubic Hamiltonian and quartic ``contact
term''. Analyzing the impurity non-conserving channel we find that the
non-perturbative, order g_2^2 sqrt(lambda') contribution to E/mu predicted in
hep-th/0211220 is in fact an artifact of these logarithmic divergences and
vanishes with them, leaving an order g_2^2 lambda' contribution. Exploiting the
supersymmetry algebra, we present a form for the energy shift which appears to
be manifestly convergent and free of non-perturbative terms. We use this form
to argue that E/mu receives order g_2^2 lambda' contributions at every order in
intermediate state impurities.Comment: 27 pages; added references, acknowledgments, missing normalization in
equations 2.3 - 2.8, also cleaned up notation, and added a few footnote
Predictions for PP-wave string amplitudes from perturbative SYM
The role of general two-impurity multi-trace operators in the BMN
correspondence is explored. Surprisingly, the anomalous dimensions of all
two-impurity multi-trace BMN operators to order g_2^2\lambda' are completely
determined in terms of single-trace anomalous dimensions. This is due to
suppression of connected field theory diagrams in the BMN limit and this fact
has important implications for some string theory processes on the PP-wave
background. We also make gauge theory predictions for the matrix elements of
the light-cone string field theory Hamiltonian in the two string-two string and
one string-three string sectors.Comment: 46 pages, 12 figures. V3:typos correcte
No absorption in de Sitter space
We study the wave equation for a minimally coupled massive scalar in
D-dimensional de Sitter space. We compute the absorption cross section to
investigate its cosmological horizon in the southern diamond. By analogy of the
quantum mechanics, it is found that there is no absorption in de Sitter space.
This means that de Sitter space is usually in thermal equilibrium, like the
black hole in anti de Sitter space. It confirms that the cosmological horizon
not only emits radiation but also absorbs that previously emitted by itself at
the same rate, keeping the curvature radius of de Sitter space fixed.Comment: 11 pages, REVTE
De Sitter Holography with a Finite Number of States
We investigate the possibility that, in a combined theory of quantum
mechanics and gravity, de Sitter space is described by finitely many states.
The notion of observer complementarity, which states that each observer has
complete but complementary information, implies that, for a single observer,
the complete Hilbert space describes one side of the horizon. Observer
complementarity is implemented by identifying antipodal states with outgoing
states. The de Sitter group acts on S-matrix elements. Despite the fact that
the de Sitter group has no nontrivial finite-dimensional unitary
representations, we show that it is possible to construct an S-matrix that is
finite-dimensional, unitary, and de Sitter-invariant. We present a class of
examples that realize this idea holographically in terms of spinor fields on
the boundary sphere. The finite dimensionality is due to Fermi statistics and
an `exclusion principle' that truncates the orthonormal basis in which the
spinor fields can be expanded.Comment: 23 pages, 1 eps figure, LaTe
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