8,128 research outputs found
Oscillating scalar-field dark matter in supergravity
We show that an oscillating scalar field in supergravity of mass of the order
of TeV with a nonzero vacuum expectation value ( GeV) can
be a candidate of cold dark matter (CDM). To avoid the gravitino problem, we
need a low reheating temperature after the primordial inflation. Then, the
energy density of the oscillating scalar field satisfies all the requirements
for CDM at present in the universe.Comment: LaTeX JHEP-format, to appear in JHE
Unified picture of Q-balls and boson stars via catastrophe theory
We make an analysis of Q-balls and boson stars using catastrophe theory, as
an extension of the previous work on Q-balls in flat spacetime. We adopt the
potential for Q-balls and
that with for boson stars. For solutions with at
its peak, stability of Q-balls has been lost regardless of the potential
parameters. As a result, phase relations, such as a Q-ball charge versus a
total Hamiltonian energy, approach those of boson stars, which tell us an
unified picture of Q-balls and boson stars.Comment: 10 pages, 13 figure
Physical Properties of UDF12 Galaxies in Cosmological simulations
We have performed a large cosmological hydrodynamics simulation tailored to
the deep survey with the Hubble Space Telescope made in 2012, the so-called
UDF12 campaign. After making a light-cone output, we have applied the same
color selection criteria as the UDF12 campaign to select galaxies from our
simulation, and then, have examined the physical properties of them as a proxy
of the real observed UDF12 galaxies at . As a result, we find that the
halo mass is almost linearly proportional to the observed ultraviolet (UV)
luminosity ( at ). The dust
attenuation and UV slope well correlates with the observed UV
luminosity, which is consistent with observations quantitatively. The star
formation rate (SFR) is also linearly proportional to the stellar mass and the
specific SFR shows only a weak dependency on the mass. We also find an
increasing star formation history with a time-scale of Myr in the
high- galaxies. An average metallicity weighted by the Lyman continuum
luminosity reaches up to Solar even at , suggesting a rapid
metal enrichment. We also expect mJy at 350 GHz of the dust thermal
emission from the galaxies with , which can be detectable with
the Atacama Large Milimetre-submilimetre Array. The galaxies selected by the
UDF12 survey contribute to only of the cosmic SFR density from to , respectively. The James Webb Space Telescope will push
the detection fraction up to .Comment: re-Submitted to MNRAS; 16 pages; 14 figures; 1 tables
PCNA Retention on DNA into G2/M Phase Causes Genome Instability in Cells Lacking Elg1
Acknowledgments We thank Richard Kolodner, Grant Brown, and Daniel Durocher for strains and plasmids. We thank Anne Donaldson, Alexander Lorenz, and Shin-ichiro Hiraga from University of Aberdeen for careful reading of the manuscript. Research in T.K.’s lab is supported by Medical Research Council Career Development Fellowship L019698/1. V.K.G. was supported by Biotechnology and Biological Sciences Research Council grant K006304/1. T.S.T. was supported by grants from the Ministry of Education, Culture, Sports, Science and Technology of Japan (nos. 23131507 and 25131712).Peer reviewedPublisher PD
Interlinked Credit and Farm Intensification: Evidence from Kenya
This paper addresses the potential for interlinked credit/input/output marketing arrangements for cash crops to promote food crop intensification. Using panel survey data from Kenya, we estimate a household fixed-effects model of fertilizer use per hectare of food crops. Results indicate that households engaging in interlinked marketing programs for selected cash crops applied considerably more fertilizer on other crops (primarily cereals) not directly purchased by the cash crop trading firm. These findings suggest that, in addition to the direct stimulus that interlinked cash crop marketing arrangements can have on small farmer incomes, these institutional arrangements may provide spillover benefits for the productivity of farmers' other activities such as food cropping.Agricultural Finance,
The Impact of Galactic Disc Environment on Star-Forming Clouds
We explore the effect of different galactic disc environments on the
properties of star-forming clouds through variations in the background
potential in a set of isolated galaxy simulations. Rising, falling and flat
rotation curves expected in halo dominated, disc dominated and Milky Way-like
galaxies were considered, with and without an additional two-arm spiral
potential. The evolution of each disc displayed notable variations that are
attributed to different regimes of stability, determined by shear and
gravitational collapse. The properties of a typical cloud were largely
unaffected by the changes in rotation curve, but the production of small and
large cloud associations was strongly dependent on this environment. This
suggests that while differing rotation curves can influence where clouds are
initially formed, the average bulk properties are effectively independent of
the global environment. The addition of a spiral perturbation made the greatest
difference to cloud properties, successfully sweeping the gas into larger,
seemingly unbound, extended structures and creating large arm-interarm
contrasts.Comment: Accepted to MNRAS on 3rd December, 201
- …