1,269 research outputs found
Forbidden Channels and SIMP Dark Matter
In this review, we focus on dark matter production from thermal freeze-out
with forbidden channels and SIMP processes. We show that forbidden channels can
be dominant to produce dark matter depending on the dark photon and / or dark
Higgs mass compared to SIMP.Comment: 5 pages, Prepared for the proceedings of the 13th International
Conference on Gravitation, 3-7 July 201
On thermal production of self-interacting dark matter
We consider thermal production mechanisms of self-interacting dark matter in
models with gauged symmetry. A complex scalar dark matter is stabilized
by the , that is the remnant of a local dark . Light dark matter
with large self-interaction can be produced from thermal freeze-out in the
presence of SM-annihilation, SIMP and/or forbidden channels. We show that dark
photon and/or dark Higgs should be relatively light for unitarity and then
assist the thermal freeze-out. We identify the constraints on the parameter
space of dark matter self-interaction and mass in cases that one or some of the
channels are important in determining the relic density.Comment: 26 pages, 11 figures, Version to appear in Journal of High Energy
Physic
Aging effects and working memory in garden-path sentence comprehension
The current study examined whether older adults exhibit difficulty in recovering from syntactically ambiguous garden-path sentences, and whether this difficulty is predicted by working memory capacity (WM). This study found several points. First, there was a garden-path effect regardless of age group. Second, there were age-related differences between young and elderly adults for the sentences with temporary syntactic ambiguity, in on- and off-line measures. Third, the age-related effects were predicted by WM. These points indicate that syntactic ambiguity resolution is affected by healthy cognitive aging, and suggest that age-related WM changes may be responsible for these differences
Unitary inflaton as decaying dark matter
We consider the inflation model of a singlet scalar field (sigma field) with
both quadratic and linear non-minimal couplings where unitarity is ensured up
to the Planck scale. We assume that a symmetry for the sigma field is
respected by the scalar potential in Jordan frame but it is broken explicitly
by the linear non-minimal coupling due to quantum gravity. We discuss the
impacts of the linear non-minimal coupling on various dynamics from inflation
to low energy, such as a sizable tensor-to-scalar ratio, a novel reheating
process with quartic potential dominance, and suppressed physical parameters in
the low energy, etc. In particular, the linear non-minimal coupling leads to
the linear couplings of the sigma field to the Standard Model through the trace
of the energy-momentum tensor in Einstein frame. Thus, regarding the sigma
field as a decaying dark matter, we consider the non-thermal production
mechanisms for dark matter from the decays of Higgs and inflaton condensate and
show the parameter space that is compatible with the correct relic density and
cosmological constraints.Comment: 36 pages, 7 figures, v2: minor corrections made and references added,
v3: discussion on preheating added, accepted for Journal of High Energy
Physics, v4: Lyman-alpha bound included and inflationary predictions refined
for perturbative reheatin
A minimal flavored for -meson anomalies
We consider an anomaly-free model with favorable couplings to heavy
flavors in the Standard Model(SM), as motivated by -meson anomalies at LHCb.
Taking the charge to be , we can
explain the -meson anomalies without invoking extra charged fermions or
flavor violation beyond the SM. We show that there is a viable parameter space
with a small that is compatible with other meson decays, tau lepton and
neutrino experiments as well as the LHC dimuon searches. We briefly discuss the
prospects of discovering the gauge boson at the LHC in the proposed model.Comment: 20 pages, 4 figures, v2: references and discussion on electroweak
precision test added, v3: Version to appear in Physical Review
Evaluation formulas for a conditional Feynman integral over Wiener paths in abstract Wiener space
summary:In this paper, we introduce a simple formula for conditional Wiener integrals over , the space of abstract Wiener space valued continuous functions. Using this formula, we establish various formulas for a conditional Wiener integral and a conditional Feynman integral of functionals on in certain classes which correspond to the classes of functionals on the classical Wiener space introduced by Cameron and Storvick. We also evaluate the conditional Wiener integral and conditional Feynman integral for functionals of the form which are of interest in Feynman integration theories and quantum mechanics
Recommended from our members
Sonographic measurements of normal gallbladder sizes in children.
PurposeOur goal was to establish the range of sonographic measurements of normal gallbladders in children.MethodsSix hundred ten children aged 0-16 years (male:female ratio, 1.5:1) with normal clinical and laboratory findings were included in this study. The sonographic parameters were the length, width, and calculated volume of the gallbladder, and the clinical parameters were the age, height, weight, and body surface area of the children. Statistical significance was determined through correlation and regression analyses.ResultsThe length of the gallbladder showed significant positive correlations with age (r = 0.65), height (r = 0.67), weight (r = 0.63), and body surface area (r = 0.65; p < 0.01). The calculated volume of the gallbladder also showed moderate correlations with age (r = 0.53), height (r = 0.55), weight (r = 0.61), and body surface area (r = 0.57; p < 0.01). The gallbladder width showed modest but significant correlations with age (r = 0.48), height (r = 0.53), weight (r = 0.53), and body surface area (r = 0.55; p < 0.01). The highest correlation coefficients were found between the gallbladder length and subject age (r = 0.65; p < 0.01) and between the gallbladder length and subject height (r = 0.67; p < 0.01). For all correlations, statistical significance remained after regression analysis (p < 0.01).ConclusionsValues for the size of the normal pediatric gallbladder are defined and will be helpful in the diagnosis of gallbladder abnormalities
Improving Neural Radiance Field using Near-Surface Sampling with Point Cloud Generation
Neural radiance field (NeRF) is an emerging view synthesis method that
samples points in a three-dimensional (3D) space and estimates their existence
and color probabilities. The disadvantage of NeRF is that it requires a long
training time since it samples many 3D points. In addition, if one samples
points from occluded regions or in the space where an object is unlikely to
exist, the rendering quality of NeRF can be degraded. These issues can be
solved by estimating the geometry of 3D scene. This paper proposes a
near-surface sampling framework to improve the rendering quality of NeRF. To
this end, the proposed method estimates the surface of a 3D object using depth
images of the training set and sampling is performed around there only. To
obtain depth information on a novel view, the paper proposes a 3D point cloud
generation method and a simple refining method for projected depth from a point
cloud. Experimental results show that the proposed near-surface sampling NeRF
framework can significantly improve the rendering quality, compared to the
original NeRF and a state-of-the-art depth-based NeRF method. In addition, one
can significantly accelerate the training time of a NeRF model with the
proposed near-surface sampling framework.Comment: 13 figures, 2 table
- …