108 research outputs found
The language of suffering: The place of pain in Louis-Ferdinand Céline's Féerie Pour Une Autre Fois I
Carax and the ambiguities - a book that needs to fail, perhaps: on Daly and Dowd's Leos Carax
In search of Frenchness lost? French Cinema in the 1990s: Continuity and Difference. Edited by Phil Powrie
Validation of a Novel Approach to Solving Multibody Systems Using Hamilton\u27s Weak Principle
A novel approach for formulating and solving for the dynamic response of multibody systems has been developed using Hamilton’s Law of Varying Action as its unifying principle. In order to assure that the associated computer program is sufficiently robust when applied across a wide range of dynamic systems, the program must be verified and validated. The purpose of the research was to perform the verification and validation of the program. Results from the program were compared with closed-form and numerical solutions of simple systems, such as a simple pendulum and a rotating pendulum. The accuracy of the program for complex systems for which there is no closed-form solution, such as a double pendulum and others, were assessed by calculating energy conservation and constraint violation. The results of this research confirm the validity of this novel approach to multibody system analysis, and pave the way for its application to increasingly complex configurations
Failure of Perturbation Theory Near Horizons: the Rindler Example
Persistent puzzles to do with information loss for black holes have
stimulated critical reassessment of the domain of validity of semiclassical EFT
reasoning in curved spacetimes, particularly in the presence of horizons. We
argue here that perturbative predictions about evolution for very long times
near a horizon are subject to problems of secular growth - i.e. powers of small
couplings come systematically together with growing functions of time. Such
growth signals a breakdown of naive perturbative calculations of late-time
behaviour, regardless of how small ambient curvatures might be. Similar issues
of secular growth also arise in cosmology, and we build evidence for the case
that such effects should be generic for gravitational fields. In particular,
inferences using free fields coupled only to background metrics can be
misleading at very late times due to the implicit assumption they make of
perturbation theory when neglecting other interactions. Using the Rindler
horizon as an example we show how this secular growth parallels similar
phenomena for thermal systems, and how it can be resummed to allow late-time
inferences to be drawn more robustly. Some comments are made about the
appearance of an IR/UV interplay in this calculation, as well as on the
possible relevance of our calculations to predictions near black-hole horizons.Comment: LaTeX, 17 pages plus appendix; added references and subsection on
back-reactio
Allegorical Geographies: Topographical Transposition and Allegorical Function in Louis-Ferdinand Céline’s Aesthetic Spaces
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