1,941 research outputs found
Binary black hole detection rates in inspiral gravitational wave searches
The signal-to-noise ratios (SNRs) for quasi-circular binary black hole
inspirals computed from restricted post-Newtonian waveforms are compared with
those attained by more complete post-Newtonian signals, which are
superpositions of amplitude-corrected harmonics of the orbital phase. It is
shown that if one were to use the best available amplitude-corrected waveforms
for detection templates, one should expect SNRs in actual searches to be
significantly lower than those suggested by simulations based purely on
restricted waveforms.Comment: 9 pages, 1 figur
Universality of efficiency at maximum power
We investigate the efficiency of power generation by thermo-chemical engines.
For strong coupling between the particle and heat flows and in the presence of
a left-right symmetry in the system, we demonstrate that the efficiency at
maximum power displays universality up to quadratic order in the deviation from
equilibrium. A maser model is presented to illustrate our argument.Comment: 4 pages, 2 figure
Critical Behaviour of Non-Equilibrium Phase Transitions to Magnetically Ordered States
We describe non-equilibrium phase transitions in arrays of dynamical systems
with cubic nonlinearity driven by multiplicative Gaussian white noise.
Depending on the sign of the spatial coupling we observe transitions to
ferromagnetic or antiferromagnetic ordered states. We discuss the phase
diagram, the order of the transitions, and the critical behaviour. For global
coupling we show analytically that the critical exponent of the magnetization
exhibits a transition from the value 1/2 to a non-universal behaviour depending
on the ratio of noise strength to the magnitude of the spatial coupling.Comment: 4 pages, 5 figure
Testing the multipole structure and conservative dynamics of compact binaries using gravitational wave observations: The spinning case
In an earlier work [S. Kastha et al., PRD {\bf 98}, 124033 (2018)], we
developed the {\it parametrized multipolar gravitational wave phasing formula}
to test general relativity, for the non-spinning compact binaries in
quasi-circular orbit. In this paper, we extend the method and include the
important effect of spins in the inspiral dynamics. Furthermore, we consider
parametric scaling of PN coefficients of the conserved energy for the compact
binary, resulting in the parametrized phasing formula for non-precessing
spinning compact binaries in quasi-circular orbit. We also compute the
projected accuracies with which the second and third generation ground-based
gravitational wave detector networks as well as the planned space-based
detector LISA will be able to measure the multipole deformation parameters and
the binding energy parameters. Based on different source configurations, we
find that a network of third-generation detectors would have comparable ability
to that of LISA in constraining the conservative and dissipative dynamics of
the compact binary systems. This parametrized multipolar waveform would be
extremely useful not only in deriving the first upper limits on any deviations
of the multipole and the binding energy coefficients from general relativity
using the gravitational wave detections, but also for science case studies of
next generation gravitational wave detectors.Comment: 16 pages, 8 figures, Mathematica readable supplemental material file
for all the inputs to calculate the parametrized waveform is with the sourc
A heat pump at a molecular scale controlled by a mechanical force
We show that a mesoscopic system such as Feynman's ratchet may operate as a
heat pump, and clarify a underlying physical picture. We consider a system of a
particle moving along an asymmetric periodic structure . When put into a
contact with two distinct heat baths of equal temperature, the system transfers
heat between two baths as the particle is dragged. We examine Onsager relation
for the heat flow and the particle flow, and show that the reciprocity
coefficient is a product of the characteristic heat and the diffusion constant
of the particle. The characteristic heat is the heat transfer between the baths
associated with a barrier-overcoming process. Because of the correlation
between the heat flow and the particle flow, the system can work as a heat pump
when the particle is dragged. This pump is particularly effective at molecular
scales where the energy barrier is of the order of the thermal energy.Comment: 7 pages, 5 figures; revise
Higher signal harmonics, LISA's angular resolution, and dark energy
It is generally believed that the angular resolution of the Laser
Interferometer Space Antenna (LISA) for binary supermassive black holes (SMBH)
will not be good enough to identify the host galaxy or galaxy cluster. This
conclusion, based on using only the dominant harmonic of the binary SMBH
signal, changes substantially when higher signal harmonics are included in
assessing the parameter estimation problem. We show that in a subset of the
source parameter space the angular resolution increases by more than a factor
of 10, thereby making it possible for LISA to identify the host galaxy/galaxy
cluster. Thus, LISA's observation of certain binary SMBH coalescence events
could constrain the dark energy equation of state to within a few percent,
comparable to the level expected from other dark energy missions.Comment: 15 pages, no figures. Final version to appear in Phys. Rev.
- …