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Resampling adaptive cloth simulations onto fixed-topology meshes
We describe a method for converting an adaptively remeshed simulation of cloth into an animated mesh with fixed topology. The topology of the mesh may be specified by the user or computed automatically. In the latter case, we present a method for computing the optimal output mesh, that is, a mesh with spatially varying resolution which is fine enough to resolve all the detail present in the animation. This technique allows adaptive simulations to be easily used in applications that expect fixed-topology animated meshes
Type IIA-Heterotic Duals With Maximal Supersymmetry
Using finite abelian automorphism groups of we construct orbifold
candidates for Type IIA-heterotic dual pairs with maximal supersymmetry in six
and lower dimensions. On the heterotic side, these results extend the series of
known reduced rank theories with maximal supersymmetry. The corresponding Type
IIA theories generalize the Schwarz and Sen proposal for the dual of the
simplest of the reduced rank theories constructed as a novel Type IIA \IZ_2
orbifold.Comment: 13 pages, harvmac (acknowledgement added and typo fixed
On the perturbative corrections around D-string instantons
We study -threshold corrections in an eight dimensional S-dual
pair of string theories, as a prototype of dual string vacua with sixteen
supercharges. We show that the orbifold CFT description of D-string instantons
gives rise to a perturbative expansion similar to the one appearing on the
fundamental string side. By an explicit calculation, using the Nambu-Goto
action in the static gauge, we show that the first subleading term agrees
precisely on the two sides. We then give a general argument to show that the
agreement extends to all orders.Comment: 12 page
AdS/CFT correspondence and D1/D5 systems in theories with 16 supercharges
We discuss spectra of supergravities, arising in the near horizon
geometry of D1/D5 systems in orbifolds/orientifolds of type IIB theory with 16
supercharges. These include models studied in a recent paper (hep-th/0012118),
where the group action involves also a shift along a transversal circle, as
well as IIB/, which is dual to IIB on . After appropriate
assignements of the orbifold group eigenvalues and degrees to the supergravity
single particle spectrum, we compute the supergravity elliptic genus and find
agreement, in the expected regime of validity, with the elliptic genus obtained
using U-duality map from (4,4) CFTs of U-dual backgrounds. Since this U-duality
involves the exchange of KK momentum and D1 charge , it allows us to
test the (4,4) CFTs in the and regimes by two different
supergravity duals.Comment: 28 pages, no figure
Worldsheet Realization of the Refined Topological String
A worldsheet realization of the refined topological string is proposed in
terms of physical string amplitudes that compute generalized N=2 F-terms of the
form F_{g,n} W^{2g}Y^{2n} in the effective supergravity action. These terms
involve the chiral Weyl superfield W and a superfield Y defined as an N=2
chiral projection of a particular anti-chiral T-bar vector multiplet. In
Heterotic and Type I theories, obtained upon compactification on the
six-dimensional manifold K3xT2, T is the usual K\"ahler modulus of the T2
torus. These amplitudes are computed exactly at the one-loop level in string
theory. They are shown to reproduce the correct perturbative part of the
Nekrasov partition function in the field theory limit when expanded around an
SU(2) enhancement point of the string moduli space. The two deformation
parameters epsilon_- and epsilon_+ of the Omega-supergravity background are
then identified with the constant field-strength backgrounds for the
anti-self-dual graviphoton and self-dual gauge field of the T-bar vector
multiplet, respectively.Comment: 35 pages, typos corrected, published in NP
Are Coronae of Magnetically Active Stars Heated by Flares? III. Analytical Distribution of Superimposed Flares
(abridged) We study the hypothesis that observed X-ray/extreme ultraviolet
emission from coronae of magnetically active stars is entirely (or to a large
part) due to the superposition of flares, using an analytic approach to
determine the amplitude distribution of flares in light curves. The
flare-heating hypothesis is motivated by time series that show continuous
variability suggesting the presence of a large number of superimposed flares
with similar rise and decay time scales. We rigorously relate the amplitude
distribution of stellar flares to the observed histograms of binned counts and
photon waiting times, under the assumption that the flares occur at random and
have similar shapes. Applying these results to EUVE/DS observations of the
flaring star AD Leo, we find that the flare amplitude distribution can be
represented by a truncated power law with a power law index of 2.3 +/- 0.1. Our
analytical results agree with existing Monte Carlo results of Kashyap et al.
(2002) and Guedel et al. (2003). The method is applicable to a wide range of
further stochastically bursting astrophysical sources such as cataclysmic
variables, Gamma Ray Burst substructures, X-ray binaries, and spatially
resolved observations of solar flares.Comment: accepted for publication in Ap
The M Theory Five-Brane and the Heterotic String
Brane actions with chiral bosons present special challenges. Recent progress
in the description of the two main examples -- the M theory five-brane and the
heterotic string -- is described. Also, double dimensional reduction of the M
theory five-brane on K3 is shown to give the heterotic string.Comment: 13 pages, latex, no figures; ICTP Conference Proceeding
Background Symmetries In Orbifolds With Discrete Wilson Lines
Target space symmetries are studied for orbifold compactified string theories
containing Wilson line background fields. The symmetries determined are for
those moduli which contribute to the string loop threshold corrections of the
gauge coupling constants. The groups found are subgroups of the modular group
and depend on the choice of discrete Wilson lines and the shape of
the underlying six-dimensional lattice.Comment: 31 pages, QMW--TH--94/0
The Life and Career of Jonathan Duncan, 1756-1795.
This thesis is a study of the life and career of Jonathan Duncan, 1756-1795. It covers his career until he left the post of Resident at Benares; the period of his governorship of Bombay has been omitted. Chapter I is a sketch of Duncan's career till his appointment to the residency of Benares. At attempt has been made to show how in his subordinate positions he received training for more responsible work. Chapter II depicts the condition of Benares at the time of his appointment and the problems which he was confronted with. In Chapter III Duncan's economic policy has been discussed with reference to his reforms in tariffs, land revenue, opium and indigo. Chapter IV deals with judicial reforms and measures for the maintenance of law and order initiated at his instance. In Chapter V his attitude to Indian society, his humanity and love for Hindu learning have been discussed; while Chapter IV deals with his achievements in Malabar - his contribution to the establishment of a regular administrative machinery, and settlements with the several Rajas. In conclusion a summary of his main reforms has been attempted, and his claims to greatness examined
Comment on the Generation Number in Orbifold Compactifications
There has been some confusion concerning the number of -forms in
orbifold compactifications of the heterotic string in numerous publications. In
this note we point out the relevance of the underlying torus lattice on this
number. We answer the question when different lattices mimic the same physics
and when this is not the case. As a byproduct we classify all symmetric
-orbifolds with world sheet supersymmetry obtaining also some new
ones.Comment: 28 pages, 9 figures not included, available in postscript at reques
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