392,869 research outputs found
Some Comments on Branes, G-flux, and K-theory
This is a summary of a talk at Strings2000 explaining three ways in which
string theory and M-theory are related to the mathematics of K-theory.Comment: 10pp., late
On Consistent Boundary Conditions for c=1 String Theory
We introduce a new parametrisation for the Fermi sea of the matrix
model. This leads to a simple derivation of the scattering matrix, and a
calculation of boundary corrections in the corresponding --dimensional
string theory. The new parametrisation involves relativistic chiral fields,
rather than the non-relativistic fields of the usual formulations. The
calculation of the boundary corrections, following recent work of Polchinski,
allows us to place restrictions on the boundary conditions in the matrix model.
We provide a consistent set of boundary conditions, but believe that they need
to be supplemented by some more subtle relationship between the space-time and
matrix model. Inspired by these boundary conditions, some thoughts on the black
hole in string theory are presented.Comment: 13 pages, 2 postscript figures include
Gauge Invariant Matrix Model for the \^A-\^D-\^E Closed Strings
The models of triangulated random surfaces embedded in (extended) Dynkin
diagrams are formulated as a gauge-invariant matrix model of Weingarten type.
The double scaling limit of this model is described by a collective field
theory with nonpolynomial interaction.
The propagator in this field theory is essentially two-loop correlator in the
corresponding string theory.Comment: 9 pages, SPhT/92-09
Place and space in early Burma: a new look at âPyu Culture'
Ancient Burma (Myanmar) is commonly split into Upper Burma âPyuâ and Lower Burma Mon cultures, an ethnic classification of walled site cultures in the Irrawaddy (Ayeyarwaddy) basin that began with fourth to ninth century C.E. scripts. The early Buddhist archaeology, however, points to multiple groups and spreads far beyond the Irrawaddy drainage system. The Mon typology has profitably been unravelled in Aung-Thwinâs controversial study (2005), but, while his advocacy of the Pyu primacy has been questioned, rudimentary definitions of the first millennium C.E. âPyu cultureâ have remained largely unchallenged. The blinkered results of text primacy in defining ethnicity and cultural identity are addressed here, with data from recent discoveries used to identify a relational engagement between the brick walls and terracotta urns typical of early Buddhist cultures in Upper Burma. This localised integration of spatial and spiritual factors is further strengthened by a range of artefacts and indigenous texts
Representations of laboratory animals in popular media forms
Attitudes to animals are in part formed through engagement with popular culture and therefore we should pay attention to the potential of this domain for shaping animal lives. But can popular culture really do anything for the âlaboratoryâ animal? This paper explores the persistent and changing deployment of the laboratory animal in a range of humorous popular media (and cultural) texts, and suggests that its appearance in comedy could provide a useful means to reach an otherwise reluctant audience
Calculation of accurate permanent dipole moments of the lowest states of heteronuclear alkali dimers using extended basis sets
The obtention of ultracold samples of dipolar molecules is a current
challenge which requires an accurate knowledge of their electronic properties
to guide the ongoing experiments. In this paper, we systematically investigate
the ground state and the lowest triplet state of mixed alkali dimers (involving
Li, Na, K, Rb, Cs) using a standard quantum chemistry approach based on
pseudopotentials for atomic core representation, gaussian basis sets, and
effective terms for core polarization effects. We emphasize on the convergence
of the results for permanent dipole moments regarding the size of the gaussian
basis set, and we discuss their predicted accuracy by comparing to other
theoretical calculations or available experimental values. We also revisit the
difficulty to compare computed potential curves among published papers, due to
the differences in the modelization of core-core interaction.Comment: accepted to J. Chem. Phy
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