4,699 research outputs found
Gravitation-Wave Emission in Shift-Symmetric Horndeski Theories
Gravity theories beyond general relativity typically predict dipolar gravitational emission by compact-star binaries. This emission is sourced by "sensitivity" parameters depending on the stellar compactness. We introduce a general formalism to calculate these parameters, and show that in shift-symmetric Horndeski theories stellar sensitivities and dipolar radiation vanish, provided that the binary's dynamics is perturbative (i.e., the post-Newtonian formalism is applicable) and cosmological-expansion effects can be neglected. This allows one to reproduce the binary-pulsar-observed orbital decay
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Perceived goal instrumentality is associated with forgiveness: A test of the valuable relationships hypothesis
Three autobiographical studies tested the valuable relationships hypothesis of forgiveness. Although previous studies revealed that relationship value predicts interpersonal forgiveness, the measure of relationship value may be conflated with affective assessments of the relationship with the transgressor, which might have caused a criterion contamination problem. Therefore, we assessed the goal-related instrumentality of the transgressor (i.e., how useful the transgressor is for helping the victim to achieve his/her goals in fitness-relevant domains). Three studies, one involving a Japanese student sample (Study 1), a second involving Japanese community sample (Study 2), and a third involving U.S. community sample (Study 3), convergently showed that perceived goal instrumentality, as well as a latent relationship value variable estimated from multiple measures of relationship value, are associated with forgiveness. Moreover, this association could be explained in part by the intermediate association of perceived goal instrumentality with empathy both in Japan and the U.S
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
CT dose reduction factors in the thousands using X-ray phase contrast
Phase-contrast X-ray imaging can improve the visibility of weakly absorbing
objects (e.g. soft tissues) by an order of magnitude or more compared to
conventional radiographs. Previously, it has been shown that combining phase
retrieval with computed tomography (CT) can increase the signal-to-noise ratio
(SNR) by up to two orders of magnitude over conventional CT at the same
radiation dose, without loss of image quality. Our experiments reveal that as
radiation dose decreases, the relative improvement in SNR increases. We
discovered this enhancement can be traded for a reduction in dose greater than
the square of the gain in SNR. Upon reducing the dose 300 fold, the
phase-retrieved SNR was still almost 10 times larger than the absorption
contrast data. This reveals the potential for dose reduction factors in the
tens of thousands without loss in image quality, which would have a profound
impact on medical and industrial imaging applications
Investigation of heavy-heavy pseudoscalar mesons in thermal QCD Sum Rules
We investigate the mass and decay constant of the heavy-heavy pseudoscalar,
, and mesons in the framework of finite temperature QCD
sum rules. The annihilation and scattering parts of spectral density are
calculated in the lowest order of perturbation theory. Taking into account the
additional operators arising at finite temperature, the nonperturbative
corrections are also evaluated. The masses and decay constants remain unchanged
under , but after this point, they start to diminish with
increasing the temperature. At critical or deconfinement temperature, the decay
constants reach approximately to 35% of their values in the vacuum, while the
masses are decreased about 7%, 12% and 2% for , and
states, respectively. The results at zero temperature are in a good consistency
with the existing experimental values as well as predictions of the other
nonperturbative approaches.Comment: 11 Pages, 2 Tables and 6 Figure
Slowly Rotating Black Holes in Dynamical Chern-Simons Gravity: Deformation Quadratic in the Spin
We derive a stationary and axisymmetric black hole solution to quadratic
order in the spin angular momentum. The previously found, linear-in-spin terms
modify the odd-parity sector of the metric, while the new corrections appear in
the even-parity sector. These corrections modify the quadrupole moment, as well
as the (coordinate-dependent) location of the event horizon and the ergoregion.
Although the linear-in-spin metric is of Petrov type D, the quadratic order
terms render it of type I. The metric does not possess a second-order Killing
tensor or a Carter-like constant. The new metric does not possess closed
timelike curves or spacetime regions that violate causality outside of the
event horizon. The new, even-parity modifications to the Kerr metric decay less
rapidly at spatial infinity than the leading-order in spin, odd-parity ones,
and thus, the former are more important when considering black holes that are
rotating moderately fast. We calculate the modifications to the Hamiltonian,
binding energy and Kepler's third law. These modifications are crucial for the
construction of gravitational wave templates for black hole binaries, which
will enter at second post-Newtonian order, just like dissipative modifications
found previously.Comment: 21 pages, 2 figures; Typos correcte
Meissner effect in honeycomb arrays of multi-walled carbon nanotubes
We report Meissner effect for type-II superconductors with a maximum Tc of 19
K, which is the highest value among those in new-carbon related
superconductors, found in the honeycomb arrays of multi-walled CNTs (MWNTs).
Drastic reduction of ferromagnetic catalyst and efficient growth of MWNTs by
deoxidization of catalyst make the finding possible. The weak magnetic
anisotropy, superconductive coherence length (- 7 nm), and disappearance of the
Meissner effect after dissolving array structure indicate that the graphite
structure of an MWNT and those intertube coupling in the honeycomb array are
dominant factors for the mechanism.Comment: 6 page
\Omega-deformation of B-twisted gauge theories and the 3d-3d correspondence
We study \Omega-deformation of B-twisted gauge theories in two dimensions. As
an application, we construct an \Omega-deformed, topologically twisted
five-dimensional maximally supersymmetric Yang-Mills theory on the product of a
Riemann surface and a three-manifold , and show that when
is a disk, this theory is equivalent to analytically continued Chern-Simons
theory on . Based on these results, we establish a correspondence between
three-dimensional superconformal theories and analytically
continued Chern-Simons theory. Furthermore, we argue that there is a mirror
symmetry between {\Omega}-deformed two-dimensional theories.Comment: 26 pages. v2: the discussion on the boundary condition for vector
multiplet improved, and other minor changes mad
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