scholarly journals Excitation of gravitational wave modes by a center-of-mass velocity of the source

2021 ◽  
Vol 104 (12) ◽  
Author(s):  
Alejandro Torres-Orjuela ◽  
Xian Chen ◽  
Pau Amaro Seoane
2021 ◽  
Author(s):  
Kazushi Fujimoto ◽  
Tetsuro Nagai ◽  
Tsuyoshi Yamaguchi

<div>The position-dependent diffusion coefficient along with free energy profile are important parameters needed to study mass transport in heterogeneous systems such as biological and polymer membranes, and molecular dynamics (MD) calculation is a popular tool to obtain them. Among many methodologies, the Marrink-Berendsen (MB) method is often employed to calculate the position-dependent diffusion coefficient, in which the autocorrelation function of the force on a fixed molecule is related to the friction on the molecule. However, the diffusion coefficient is shown to be affected by the period of the removal of the center-of-mass velocity, which is necessary when performing MD calculations using the Ewald method for Coulombic interaction. We have clarified theoretically in this study how this operation affects the diffusion coefficient calculated by the MB method, and the theoretical predictions are proven by MD calculations. Therefore, we succeeded in providing guidance on how to select an appropriate the period of the removal of the center-of-mass velocity in estimating the position-dependent diffusion coefficient by the MB method. This guideline is applicable also to the Woolf-Roux method.</div>


2010 ◽  
Vol 19 (3-4) ◽  
Author(s):  
J. Sperauskas ◽  
A. Bartkevičius ◽  
R. P. Boyle ◽  
V. Deveikis

AbstractThe spectroscopic orbit of a high proper motion star, BD+20 5152, is calculated from 34 CORAVEL-type radial velocity measurements. The star has a slightly eccentric orbit with a period of 5.70613 d, half-amplitude of 47.7 km/s and eccentricity of 0.049. The center-of-mass velocity of the system is -24.3 km/s. BD+20 5152 seems to be a triple system consisting of a G8 dwarf as a primary component and of two K6-M0 dwarfs as secondary and tertiary components. This model is based on the analysis of its UBVRI and JHK magnitudes. According to the SuperWASP photometry, spots on the surface of the primary are suspected. The excessive brightness in the Galex FUV and NUV magnitudes and a non-zero eccentricity suggest the age of this system to be less than 1 Gyr.


Symmetry ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1318 ◽  
Author(s):  
Rui Xu

General Relativity predicts two modes for plane gravitational waves. When a tiny violation of Lorentz invariance occurs, the two gravitational wave modes are modified. We use perturbation theory to study the detailed form of the modifications to the two gravitational wave modes from the minimal Lorentz-violation coupling. The perturbation solution for the metric fluctuation up to the first order in Lorentz violation is discussed. Then, we investigate the motions of test particles under the influence of the plane gravitational waves with Lorentz violation. First-order deviations from the usual motions are found.


2014 ◽  
Vol 39 ◽  
pp. S11-S12 ◽  
Author(s):  
Philippe C. Dixon ◽  
Julie Stebbins ◽  
Tim Theologis ◽  
Amy B. Zavatsky

1998 ◽  
Vol 13 (20) ◽  
pp. 1653-1665 ◽  
Author(s):  
JOHN ARGYRIS ◽  
CORNELIU CIUBOTARIU

In this letter we signalize the possibility of applying a quantum chaos as an element of high sensitivity which serves to detect small changes in length generated by gravitational waves. We propose the construction of a double-bar antenna with a coupling Josephson junction in its center-of-mass. In fact the new antenna is a single Josephson junction with massive bulk contacts, like a single-junction SQUID but with free ends. Computer experiments demonstrate that very small changes generated by the variation of the distance between the bulk plates of the junction capacitance will produce a variety of very different intermittency routes to chaos. A concrete numerical example illustrates the smallness of a quantum of chaos and thus the extraordinary sensitivity of the proposed method.


Author(s):  
Zhuohua Shen ◽  
Justin Seipel

A reduced model of legged locomotion, called the Spring Loaded Inverted Pendulum (SLIP) has previously been developed to predict the dynamics of locomotion. However, due to energy conservation, the SLIP model can only be partially asymptotically stable in the center-of-mass velocity. The more recently developed Clock-Torqued Spring Loaded Inverted Pendulum (CT-SLIP) model is fully asymptotically stable, and has a significantly larger stability basin than SLIP, but requires more than twice as many parameters. To more completely explore the parameter space and understand the reason for improved stability, we develop and analyze a further reduced model called the Forced-Damped Spring Loaded Inverted Pendulum (FD-SLIP) model.


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