4,696 research outputs found
Remarks on the Additional Symmetries and W-Constraints in the Generalized KdV Hierarchy
Additional symmetries of the -reduced KP hierarchy are generated by the
Lax operator and another operator , satisfying = 0
for and with the condition that = 0, = 1, 2,..... We show explicitly that the
generators of these additional symmetries satisfy a closed and consistent
W-algebra only when we impose the extra condition that .Comment: 10 pages, Plain Te
The sTB-B Hierarchy
We construct a new supersymmetric two boson (sTB-B) hierarchy and study its
properties. We derive the conserved quantities and the Hamiltonian structures
(proving the Jacobi identity) for the system. We show how this system gives the
sKdV-B equation and its Hamiltonian structures upon appropriate reduction. We
also describe the zero curvature formulation of this hierarchy both in the
superspace as well as in components.Comment: 15 pages, Te
Light-Cone Quantization of the c=2 Matrix Model
We study the large limit of an interacting \td\ matrix field theory,
whose perturbative expansion generates the sum over planar random graphs
embedded in two dimensions. In the \lc\ quantization the theory possesses
closed string excitations which become free as . If the
longitudinal momenta are discretized, then the calculation of the free string
spectrum reduces to finite matrix diagonalization, the size of the matrix
growing as the cut-off is removed. Our numerical results suggest that, for a
critical coupling, the \lc\ string spectrum becomes continuous. This would
indicate the massless dynamics of the Liouville mode of \td\ gravity, which
would constitute a {\it third} dimension of the string theory.Comment: 12 pages, (3 diagrams now available as postscript files from authors,
1 ref added), PUPT-133
*-Trek II: *_n Operations, Open Wilson Lines and the Seiberg-Witten Map
Generalizations of the *-product (e.g. n-ary *_n operations) appear in
various places in the discussion of noncommutative gauge theories. These
include the one-loop effective action of noncommutative gauge theories, the
couplings between massless closed and open string modes, and the Seiberg-Witten
map between the ordinary and noncommutative Yang-Mills fields. We propose that
the natural way to understand the *_n operations is through the expansion of an
open Wilson line. We establish the connection between an open Wilson line and
the *_n operations and use it to: (I) write down a gauge invariant effective
action for the one-loop F^4 terms in the noncommutative N=4 SYM theory; (II)
find the gauge invariant couplings between the noncommutative SYM modes and the
massless closed string modes in flat space; (III) propose a closed form for the
Seiberg-Witten map in the U(1) case.Comment: 30 pages, AMSLaTeX using JHEP.cls., clarifications made, misprints
corrected, references adde
Gauge Invariant Correlators in Non-Commutative Gauge Theory
Using perturbation theory, we explore the universal high momentum behavior of
correlation functions of gauge invariant operators in planar noncommutative
gauge theories. We find that the correlation functions are strongly enhanced
when pairs of momenta become antiparallel. In particular, there is a transition
from the previously noted exponential suppression of correlation functions at
high momenta to a more field theoretic behavior when the momenta of pairs of
operators antialign within a critical angle. Some of our calculations can be
extrapolated to strong coupling, and in particular we are able to reproduce
precisely the supergravity prediction for the behavior of two point functions,
including the coupling dependence.Comment: 24 pages, LaTeX, 6 figure
Tobacco use disorder and treatment: new challenges and opportunities
Tobacco use remains a global problem, and options for consumers have increased with the development and marketing of e-cigarettes and other new nicotine and tobacco products, such as heat-not-burn tobacco and dissolvable tobacco. The increased access to these new products is juxtaposed with expanding public health and clinical intervention options, including mobile technologies and social media. The persistent high rate of tobacco-use disorders among those with psychiatric disorders has gathered increased global attention, including successful approaches to individual treatment and organizational-level interventions. Best outcomes occur when medications are integrated with behavioral therapies and community-based interventions. Addressing tobacco in mental health settings requires training and technical assistance to remove old cultural barriers that restricted interventions. There is still low-hanging fruit to be gained in educating on the proper use of nicotine replacement medications, how smoking cessation can change blood levels of specific medications and caffeine, and how to connect with quitlines and mobile technology options. Future innovations are likely to be related to pharmacogenomics and new technologies that are human-, home-, and community-facing
Loops in the Curvature Matrix Model
Macroscopic loop correlators are investigated in the hermitian one matrix
model with the potential perturbed by the higher order curvature term. In the
phase of smooth surfaces the model is equivalent to the minimal conformal
matter coupled to gravity. The properties of the model in the intermediate
phase are similar to that of the discretized bosonic string with the central
charge Loop correlators describe the effect of the splitting of the
random surfaces. It is shown, that the properties of the surfaces are changed
in the intermediate phase because the perturbation modifies the spectrum of the
scaling operators.Comment: UPRF-92-340, 14 pages, 3 figures, LaTeX fil
On the energy-momentum tensor in non-commutative gauge theories
We study the properties of the energy-momentum tensor in non-commutative
gauge theories by coupling them to a weak external gravitational field. In
particular, we show that the stress tensor of such a theory coincides exactly
with that derived from a theory where a Seiberg-Witten map has been implemented
(namely, the procedure is commutative). Various other interesting features are
also discussed.Comment: 3 page
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