4,327 research outputs found
Gravitational Wave Background from Neutrino-Driven Gamma-Ray Bursts
We discuss the gravitational wave background (GWB) from a cosmological
population of gamma-ray bursts (GRBs). Among various emission mechanisms for
the gravitational waves (GWs), we pay a particular attention to the vast
anisotropic neutrino emissions from the accretion disk around the black hole
formed after the so-called failed supernova explosions. The produced GWs by
such mechanism are known as burst with memory, which could dominate over the
low-frequency regime below \sim 10Hz. To estimate their amplitudes, we derive
general analytic formulae for gravitational waveform from the axisymmetric
jets. Based on the formulae, we first quantify the spectrum of GWs from a
single GRB. Then, summing up its cosmological population, we find that the
resultant value of the density parameter becomes roughly \Omega_{GW} \approx
10^{-20} over the wide-band of the low-frequency region, f\sim 10^{-4}-10^1Hz.
The amplitude of GWB is sufficiently smaller than the primordial GWBs
originated from an inflationary epoch and far below the detection limit.Comment: 6 pages, 4 figures, accepted for publication in MNRA
Unbinding Transition Induced by Osmotic Pressure in Relation to Unilamellar Vesicle Formation
Small-angle X-ray scattering and phase-contrast microscopy experiments were
performed to investigate the effect of the osmotic pressure on vesicle
formation in a dioleoylphosphatidylcholine (DOPC)/water/NaI system.
Multi-lamellar vesicles were formed when a pure lipid film was hydrated with an
aqueous solution of NaI. On the other hand, uni-lamellar vesicles (ULVs) were
formed when a lipid film mixed with an enough amount of NaI was hydrated. To
confirm the effect of the osmotic pressure due to NaI, a free-energy
calculation was performed. This result showed that the osmotic pressure induced
an unbinding transition on the hydration process, which resulted in ULV
formation
F-term Moduli Stabilization and Uplifting
We study K\"ahler moduli stabilization in IIB superstring theory. We propose
a new moduli stabilization mechanism by the supersymmetry-braking chiral
superfield which is coupled to K\"ahler moduli in K\"ahler potential. We also
study uplifting of the Large Volume Scenario (LVS) by it. In both cases, the
form of superpotential is crucial for moduli stabilization. We confirm that our
uplifting mechanism does not destabilize the vacuum of the LVS drastically.Comment: 22 pages, 2 figure
Intermediate states at structural phase transition: Model with a one-component order parameter coupled to strains
We study a Ginzburg-Landau model of structural phase transition in two
dimensions, in which a single order parameter is coupled to the tetragonal and
dilational strains. Such elastic coupling terms in the free energy much affect
the phase transition behavior particularly near the tricriticality. A
characteristic feature is appearance of intermediate states, where the ordered
and disordered regions coexist on mesoscopic scales in nearly steady states in
a temperature window. The window width increases with increasing the strength
of the dilational coupling. It arises from freezing of phase ordering in
inhomogeneous strains. No impurity mechanism is involved. We present a simple
theory of the intermediate states to produce phase diagrams consistent with
simulation results.Comment: 16 pages, 14 figure
Информационный бюллетень. Белинка. Даты. События. Люди. Июнь. 2014
Mobile dating apps have become a popular means to meet potential partners.
Although several exist, one recent addition stands out amongst all others.
Tinder presents its users with pictures of people geographically nearby, whom
they can either like or dislike based on first impressions. If two users like
each other, they are allowed to initiate a conversation via the chat feature.
In this paper we use a set of curated profiles to explore the behaviour of men
and women in Tinder. We reveal differences between the way men and women
interact with the app, highlighting the strategies employed. Women attain large
numbers of matches rapidly, whilst men only slowly accumulate matches. To
expand on our findings, we collect survey data to understand user intentions on
Tinder. Most notably, our results indicate that a little effort in grooming
profiles, especially for male users, goes a long way in attracting attention
- …