3,181 research outputs found
Higher Derivative Corrections to O-plane Actions: NS-NS Sector
We classify all possible two- and four-derivative couplings of bulk NS-NS
sector fields to a single Op-plane which are compatible with diffeomorphism
invariance and B-field gauge invariance. This is applicable to type IIA or IIB
superstrings or to the bosonic string. We then consider this general action in
various classes of backgrounds that admit a U(1) isometry and determine the
constraints on the couplings from consistency with T-duality. We show that this
consistency requires the two-derivative action to vanish, and the entire
non-linear four-derivative action is fixed up to one overall constant which can
be determined by comparison with a two-point scattering amplitude. The
resulting action is consistent with all previously computed couplings.Comment: 54 page
Public Health Versus Court-Sponsored Secrecy
Public health practice relies on access to information. Givelber and Robbins discuss the debate about court-sponsored secrecy: Whether or not courts should tolerate, edorse, or protect secrecy when the sequestered information might help protect the public health
Kaluza-Klein Theories Without Truncation
In this note we present a closed expression for the space-time effective
action for all bosonic fields (massless and massive) obtained from the
compactification of gravity or supergravity theories (such as type II or
eleven-dimensional supergravities) from to space-time dimensions.Comment: 20 page
Scalar-Vector Bootstrap
We work out all of the details required for implementation of the conformal
bootstrap program applied to the four-point function of two scalars and two
vectors in an abstract conformal field theory in arbitrary dimension. This
includes a review of which tensor structures make appearances, a construction
of the projectors onto the required mixed symmetry representations, and a
computation of the conformal blocks for all possible operators which can be
exchanged. These blocks are presented as differential operators acting upon the
previously known scalar conformal blocks. Finally, we set up the bootstrap
equations which implement crossing symmetry. Special attention is given to the
case of conserved vectors, where several simplifications occur.Comment: 76 pages, v3 moved several details into appendices, expanded
discussion of mixed symmetry projecto
Abelian Tensor Hierarchy in 4D, N=1 Superspace
With the goal of constructing the supersymmetric action for all fields,
massless and massive, obtained by Kaluza-Klein compactification from type II
theory or M-theory in a closed form, we embed the (Abelian) tensor hierarchy of
p-forms in four-dimensional, N=1 superspace and construct its Chern-Simons-like
invariants. When specialized to the case in which the tensors arise from a
higher-dimensional theory, the invariants may be interpreted as
higher-dimensional Chern-Simons forms reduced to four dimensions. As an
application of the formalism, we construct the eleven-dimensional Chern-Simons
form in terms of four-dimensional, N=1 superfields.Comment: 31 page
Cartography of high-dimensional flows: A visual guide to sections and slices
Symmetry reduction by the method of slices quotients the continuous
symmetries of chaotic flows by replacing the original state space by a set of
charts, each covering a neighborhood of a dynamically important class of
solutions, qualitatively captured by a `template'. Together these charts
provide an atlas of the symmetry-reduced `slice' of state space, charting the
regions of the manifold explored by the trajectories of interest. Within the
slice, relative equilibria reduce to equilibria and relative periodic orbits
reduce to periodic orbits. Visualizations of these solutions and their unstable
manifolds reveal their interrelations and the role they play in organizing
turbulence/chaos.Comment: 12 Pages, 12 figure
Some tree-level string amplitudes in the NSR formalism
We calculate tree level scattering amplitudes for open strings using the NSR
formalism. We present a streamlined symmetry-based and pedagogical approach to
the computations, which we first develop by checking two-, three-, and
four-point functions involving bosons and fermions. We calculate the five-point
amplitude for massless gluons and find agreement with an earlier result by
Brandt, Machado and Medina. We then compute the five-point amplitudes involving
two and four fermions respectively, the general form of which has not been
previously obtained in the NSR formalism. The results nicely confirm
expectations from the supersymmetric effective action. Finally we use the
prescription of Kawai, Lewellen and Tye (KLT) to compute the amplitudes for the
closed string sector.Comment: 40+8 pages; v2: references added; v3: additional field theory checks
made; published version; v4: minor corrections; results unchange
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