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 $10^4$ binaries to estimate the determination accuracy of binary parameters including the Brans-Dicke parameter $\omega_{\mathrm{BD}}$ and the graviton Compton length $\lambda_g$. Assuming a $(1.4, 10)M_{\odot}$ NS/BH binary of SNR=$\sqrt{200}$, the constraint on $\omega_{\mathrm{BD}}$ is obtained as $\omega_{\mathrm{BD}}>2.32\times 10^6$, 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 $O(10^4)$ yr$^{-1}$, a statistical analysis yields $\omega_{\mathrm{BD}}>3.77\times10^8$, which is 4 orders of magnitude stronger than the current strongest bound obtained from the solar system experiment. For massive graviton theories, assuming a $(10^6, 10^5)M_{\odot}$ BH/BH binary at 3Gpc, one can put a constraint $\lambda_g>3.35\times10^{20}$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

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

Direct observation of the mass renormalization in SrVO3_3 by angle resolved photoemission spectroscopy

We have performed an angle-resolved photoemission study of the three-dimensional perovskite-type SrVO$_3$. Observed spectral weight distribution of the coherent part in the momentum space shows cylindrical Fermi surfaces consisting of the V 3$d$ $t_{2g}$ 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

Forage Quality, Yield and Palatability of Quackgrass (\u3ci\u3eElytrigia repens\u3c/i\u3e (L.) Nevski)

Quackgrass (Elytrigia repens (L.) Nevski) is a competitive perennial invader of pastures and hay meadows which is frequently harvested as forage in mixtures with desired forage species. Field experiments were conducted to compare quackgrass with cool-season perennial grasses grown under the same soil and climatic conditions, in terms of forage quality, productivity, and palatability. The forage quality of the hays was influenced by the grass species. Quackgrass showed forage crude protein (CP) concentration that was equal to those of perennial ryegrass (Lolium perenne), reed canarygrass (Phalaris arundinacea) and Kentucky bluegrass (Poa pratensis), and greater than orchardgrass (Dactylis glomerata). The neutral detergent fiber (NDF) acid detergent fiber (ADF) concentration of the quackgrass was intermediate between those of perennial ryegrass and Kentucky bluegrass. Yields of quackgrass was equal to reed canarygrass, and greater than those of Kentucky bluegrass, orchardgrass and perennial ryegrass. The different hays did not affect the response of animals by feed intake. Quackgrass hay had higher phosphorus (P) and potassium (K) concentration, and lower calcium (Ca), magnesium (Mg) concentrations. Quackgrass was not to be inferior to other cool-season perennial grasses under frequent utilization