1,180 research outputs found
A Gluing Construction Regarding Point Particles in General Relativity
We develop a gluing construction which adds scaled and truncated
asymptotically Euclidean solutions of the Einstein constraint equations to
compact solutions with potentially non-trivial cosmological constants. The
result is a one-parameter family of initial data which has ordinary and scaled
"point-particle" limits analogous to those of Gralla and Wald ("A rigorous
derivation of gravitational self-force," Class. Quantum Grav. 2008). In
particular, we produce examples of initial data which generalize Schwarzschild
- de Sitter initial data and gluing theorems of IMP-type
Thrombolyse der Arteria cerebri media
Zusammenfassung: In den ersten 3h nach Eintritt eines akuten ischämischen Hirninfarkts ist die intravenöse Thrombolyse (IVT) die evidenzbasierte Therapie (IVT 3-4,5h: "off-label use" mit Einverständnis des Patienten). Die intraarterielle Thrombolyse (IAT) führt in der A.cerebri media (ACM) allerdings häufiger zur Rekanalisation als die IVT. Daher ist die IAT in dafür ausgerüsteten Kliniken ergänzend oder alternativ zur IVT bis zu 6h nach Symptombeginn zu erwäge
Electromagnetic self-forces and generalized Killing fields
Building upon previous results in scalar field theory, a formalism is
developed that uses generalized Killing fields to understand the behavior of
extended charges interacting with their own electromagnetic fields. New notions
of effective linear and angular momenta are identified, and their evolution
equations are derived exactly in arbitrary (but fixed) curved spacetimes. A
slightly modified form of the Detweiler-Whiting axiom that a charge's motion
should only be influenced by the so-called "regular" component of its
self-field is shown to follow very easily. It is exact in some interesting
cases, and approximate in most others. Explicit equations describing the
center-of-mass motion, spin angular momentum, and changes in mass of a small
charge are also derived in a particular limit. The chosen approximations --
although standard -- incorporate dipole and spin forces that do not appear in
the traditional Abraham-Lorentz-Dirac or Dewitt-Brehme equations. They have,
however, been previously identified in the test body limit.Comment: 20 pages, minor typos correcte
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