6,372 research outputs found
DECIGO/BBO as a probe to constrain alternative theories of gravity
We calculate how strongly one can constrain the alternative theories of
gravity with deci-Hz gravitational wave interferometers such as DECIGO and BBO.
Here we discuss Brans-Dicke theory and massive graviton theories as typical
examples. We consider the inspiral of compact binaries composed of a neutron
star (NS) and an intermediate mass black hole (IMBH) for Brans-Dicke (BD)
theory and those composed of a super massive black hole (SMBH) and a black hole
(SMBH) for massive graviton theories. Using the restricted 2PN waveforms
including spin effects and taking the spin precession into account, we perform
the Monte Carlo simulations of binaries to estimate the determination
accuracy of binary parameters including the Brans-Dicke parameter
and the graviton Compton length . Assuming a
NS/BH binary of SNR=, the constraint on
is obtained as ,
which is 300 times stronger than the estimated constraint from LISA
observation. Furthermore, we find that, due to the expected large merger rate
of NS/BH binaries of yr, a statistical analysis yields
, which is 4 orders of magnitude stronger
than the current strongest bound obtained from the solar system experiment. For
massive graviton theories, assuming a BH/BH binary at
3Gpc, one can put a constraint cm, on average.
This is three orders of magnitude stronger than the one obtained from the solar
system experiment. From these results, it is understood that DECIGO/BBO is a
very powerful tool for constraining alternative theories of gravity, too.Comment: 4 pages, 3 figures; Accepted to Prog. Theor. Phys. Letters; Many
interpretations and some references have been added; Some Coding errors being
corrected and the final constraints came out stronge
Direct observation of the mass renormalization in SrVO by angle resolved photoemission spectroscopy
We have performed an angle-resolved photoemission study of the
three-dimensional perovskite-type SrVO. Observed spectral weight
distribution of the coherent part in the momentum space shows cylindrical Fermi
surfaces consisting of the V 3 orbitals as predicted by
local-density-approximation (LDA) band-structure calculation. The observed
energy dispersion shows a moderately enhanced effective mass compared to the
LDA results, corresponding to the effective mass enhancement seen in the
thermodynamic properties. Contributions from the bulk and surface electronic
structures to the observed spectra are discussed based on model calculations.Comment: 5 pages, 5 figure
Supersymmetric N=1 Spin(10) Gauge Theory with Two Spinors via a-Maximization
We give a detailed analysis of the superconformal fixed points of
four-dimensional N=1 supersymmetric Spin(10) gauge theory with two spinors and
vectors by using a-maximization procedure.Comment: 24 pages, 4 figures, harvma
Measurements of Thermophysical Property of Thin Films by Light Pulse Heating Thermoreflectance Methods
Thermoreflectance methods by picosecond pulse heating and by nanosecond pulse
heating have been developed under the same geometrical configuration as the
laser flash method by the National Metrology Institute of JAPAN, AIST. Using
these light pulse heating methods, thermal diffusivity of each layer of
multilayered thin films and boundary thermal resistance between the layers can
be determined from the observed transient temperature curves based on the
response function method. The measurement results of various thin films as
transparent conductive films used for flat panel displays, hard coating films
and multilayered films of the next generation phase-change optical disk will be
presented.Comment: Submitted on behalf of TIMA Editions
(http://irevues.inist.fr/tima-editions
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