3,266 research outputs found
Assessment of Metabolic Parameters For Autism Spectrum Disorders
Autism is a brain development disorder that first appears during infancy or childhood, and generally follows a steady course without remission. Impairments result from maturation-related changes in various systems of the brain. Autism is one of the five pervasive developmental disorders (PDD), which are characterized by widespread abnormalities of social interactions and communication, and severely restricted interests and highly repetitive behavior. The reported incidence of autism spectrum disorders (ASDs) has increased markedly over the past decade. The Centre for Disease Control and Prevention has recently estimated the prevalence of ASDs in the United States at approximately 5.6 per 1000 (1 of 155 to 1 of 160) children. Several metabolic defects, such as phenylketonuria, are associated with autistic symptoms. In deciding upon the appropriate evaluation scheme a clinician must consider a host of different factors. The guidelines in this article have been developed to assist the clinician in the consideration of these factors
Limits of minimal models and continuous orbifolds
The lambda=0 't Hooft limit of the 2d W_N minimal models is shown to be
equivalent to the singlet sector of a free boson theory, thus paralleling
exactly the structure of the free theory in the Klebanov-Polyakov proposal. In
2d, the singlet sector does not describe a consistent theory by itself since
the corresponding partition function is not modular invariant. However, it can
be interpreted as the untwisted sector of a continuous orbifold, and this point
of view suggests that it can be made consistent by adding in the appropriate
twisted sectors. We show that these twisted sectors account for the `light
states' that were not included in the original 't Hooft limit. We also show
that, for the Virasoro minimal models (N=2), the twisted sector of our orbifold
agrees precisely with the limit theory of Runkel & Watts. In particular, this
implies that our construction satisfies crossing symmetry.Comment: 33 pages; v2: minor improvements and references added, published
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Routing Games over Time with FIFO policy
We study atomic routing games where every agent travels both along its
decided edges and through time. The agents arriving on an edge are first lined
up in a \emph{first-in-first-out} queue and may wait: an edge is associated
with a capacity, which defines how many agents-per-time-step can pop from the
queue's head and enter the edge, to transit for a fixed delay. We show that the
best-response optimization problem is not approximable, and that deciding the
existence of a Nash equilibrium is complete for the second level of the
polynomial hierarchy. Then, we drop the rationality assumption, introduce a
behavioral concept based on GPS navigation, and study its worst-case efficiency
ratio to coordination.Comment: Submission to WINE-2017 Deadline was August 2nd AoE, 201
Supersymmetric holography on AdS3
The proposed duality between Vasiliev's supersymmetric higher spin theory on
AdS3 and the 't Hooft limit of the 2d superconformal Kazama-Suzuki models is
analysed in detail. In particular, we show that the partition functions of the
two theories agree in the large N limit.Comment: 25 pages, 3 figures, improved fig.
Minimal Model Holography for SO(2N)
A duality between the large N 't Hooft limit of the WD_N minimal model CFTs
and a higher spin gravity theory on AdS3 is proposed. The gravity theory has
massless spin fields of all even spins s=2,4,6,..., as well as two real scalar
fields whose mass is determined by the 't Hooft parameter of the CFT. We show
that, to leading order in the large N limit, the 1-loop partition function of
the higher spin theory matches precisely with the CFT partition function.Comment: 21 pages, LaTe
Higher Spin Gravity with Matter in AdS_3 and Its CFT Dual
We study Vasiliev's system of higher spin gauge fields coupled to massive
scalars in AdS_3, and compute the tree level two and three point functions.
These are compared to the large N limit of the W_N minimal model, and
nontrivial agreements are found. We propose a modified version of the
conjecture of Gaberdiel and Gopakumar, under which the bulk theory is
perturbatively dual to a subsector of the CFT that closes on the sphere.Comment: 58 pages; typos corrected, references adde
Light States in Chern-Simons Theory Coupled to Fundamental Matter
Motivated by developments in vectorlike holography, we study SU(N)
Chern-Simons theory coupled to matter fields in the fundamental representation
on various spatial manifolds. On the spatial torus T^2, we find light states at
small `t Hooft coupling \lambda=N/k, where k is the Chern-Simons level, taken
to be large. In the free scalar theory the gaps are of order \sqrt {\lambda}/N
and in the critical scalar theory and the free fermion theory they are of order
\lambda/N. The entropy of these states grows like N Log(k). We briefly consider
spatial surfaces of higher genus. Based on results from pure Chern-Simons
theory, it appears that there are light states with entropy that grows even
faster, like N^2 Log(k). This is consistent with the log of the partition
function on the three sphere S^3, which also behaves like N^2 Log(k). These
light states require bulk dynamics beyond standard Vasiliev higher spin gravity
to explain them.Comment: 58 pages, LaTeX, no figures, Minor error corrected, references added,
The main results of the paper have not change
Bi-local Construction of Sp(2N)/dS Higher Spin Correspondence
We derive a collective field theory of the singlet sector of the Sp(2N) sigma
model. Interestingly the hamiltonian for the bilocal collective field is the
same as that of the O(N) model. However, the large-N saddle points of the two
models differ by a sign. This leads to a fluctuation hamiltonian with a
negative quadratic term and alternating signs in the nonlinear terms which
correctly reproduces the correlation functions of the singlet sector. Assuming
the validity of the connection between O(N) collective fields and higher spin
fields in AdS, we argue that a natural interpretation of this theory is by a
double analytic continuation, leading to the dS/CFT correspondence proposed by
Anninos, Hartman and Strominger. The bi-local construction gives a map into the
bulk of de Sitter space-time. Its geometric pseudospin-representation provides
a framework for quantization and definition of the Hilbert space. We argue that
this is consistent with finite N grassmanian constraints, establishing the
bi-local representation as a nonperturbative framework for quantization of
Higher Spin Gravity in de Sitter space.Comment: 1 figur
Quivers, words and fundamentals
40 pages + Appendices, 9 figures40 pages + Appendices, 9 figure
Asymptotic W-symmetries in three-dimensional higher-spin gauge theories
We discuss how to systematically compute the asymptotic symmetry algebras of
generic three-dimensional bosonic higher-spin gauge theories in backgrounds
that are asymptotically AdS. We apply these techniques to a one-parameter
family of higher-spin gauge theories that can be considered as large N limits
of SL(N) x SL(N) Chern-Simons theories, and we provide a closed formula for the
structure constants of the resulting infinite-dimensional non-linear
W-algebras. Along the way we provide a closed formula for the structure
constants of all classical W_N algebras. In both examples the higher-spin
generators of the W-algebras are Virasoro primaries. We eventually discuss how
to relate our basis to a non-primary quadratic basis that was previously
discussed in literature.Comment: 61 page
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