127 research outputs found
Research Update on Extreme-Mass-Ratio Inspirals
The inspirals of stellar-mass mass compact objects into massive black holes
in the centres of galaxies are one of the most important sources of
gravitational radiation for space-based detectors like LISA or eLISA. These
extreme-mass-ratio inspirals (EMRIs) will enable an ambitious research program
with implications for astrophysics, cosmology, and fundamental physics. This
article is a summary of the talks delivered at the plenary session on EMRIs at
the 10th International LISA Symposium. It contains research updates on the
following topics: astrophysics of EMRIs; EMRI science potential; and EMRI
modeling.Comment: 17 pages, no figures. Proceedings of the LISA Symposium X, to be
published at the Journal of Physic
Test of the weak cosmic censorship conjecture with a charged scalar field and dyonic Kerr-Newman black holes
A thought experiment considered recently in the literature, in which it is
investigated whether a dyonic Kerr-Newman black hole can be destroyed by
overcharging or overspinning it past extremality by a massive complex scalar
test field, is revisited. Another derivation of the result that this is not
possible, i.e. the weak cosmic censorship is not violated in this thought
experiment, is given. The derivation is based on conservation laws, on a null
energy condition, and on specific properties of the metric and the
electromagnetic field of dyonic Kerr-Newman black holes. The metric is kept
fixed, whereas the dynamics of the electromagnetic field is taken into account.
A detailed knowledge of the solutions of the equations of motion is not needed.
The approximation in which the electromagnetic field is fixed is also
considered, and a derivation for this case is also given. In addition, an older
version of the thought experiment, in which a pointlike test particle is used,
is revisited. The same result, namely the non-violation of the cosmic
censorship, is rederived in a way which is simpler than in earlier works.Comment: 18 pages, LaTe
Carbon Monoxide Induced Erythroid Differentiation of K562 Cells Mimics the Central Macrophage Milieu in Erythroblastic Islands
Growing evidence supports the role of erythroblastic islands (EI) as microenvironmental niches within bone marrow (BM), where cell-cell attachments are suggested as crucial for erythroid maturation. The inducible form of the enzyme heme oxygenase, HO-1, which conducts heme degradation, is absent in erythroblasts where hemoglobin (Hb) is synthesized. Yet, the central macrophage, which retains high HO-1 activity, might be suitable to take over degradation of extra, harmful, Hb heme. Of these enzymatic products, only the hydrophobic gas molecule - CO can transfer from the macrophage to surrounding erythroblasts directly via their tightly attached membranes in the terminal differentiation stage
Self-force: Computational Strategies
Building on substantial foundational progress in understanding the effect of
a small body's self-field on its own motion, the past 15 years has seen the
emergence of several strategies for explicitly computing self-field corrections
to the equations of motion of a small, point-like charge. These approaches
broadly fall into three categories: (i) mode-sum regularization, (ii) effective
source approaches and (iii) worldline convolution methods. This paper reviews
the various approaches and gives details of how each one is implemented in
practice, highlighting some of the key features in each case.Comment: Synchronized with final published version. Review to appear in
"Equations of Motion in Relativistic Gravity", published as part of the
Springer "Fundamental Theories of Physics" series. D. Puetzfeld et al.
(eds.), Equations of Motion in Relativistic Gravity, Fundamental Theories of
Physics 179, Springer, 201
Heterogeneity of clinical indices among the older dialysis population—a study on Japanese dialysis population
Primary neuroendocrine neoplasm of the esophagus – Report of 14 cases from a single institute and review of the literature
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