6,642 research outputs found
Bootstrapping 2D CFTs in the Semiclassical Limit
We study two dimensional conformal field theories in the semiclassical limit.
In this limit, the four-point function is dominated by intermediate primaries
of particular weights along with their descendants, and the crossing equations
simplify drastically. For a four-point function receiving sufficiently small
contributions from the light primaries, the structure constants involving heavy
primaries follow a universal formula. Applying our results to the four-point
function of the twist field in the symmetric product orbifold, we
produce the Hellerman bound and the logarithmically corrected Cardy formula
that is valid for .Comment: 32 pages, 7 figures. v2, v3: references added, minor clarification
Neurotensin : a study of its distribution, release and metabolism
Imperial Users onl
Carving Out the End of the World or (Superconformal Bootstrap in Six Dimensions)
We bootstrap superconformal field theories in six
dimensions, by analyzing the four-point function of flavor current multiplets.
Assuming flavor group, we present universal bounds on the central charge
and the flavor central charge . Based on the numerical data, we
conjecture that the rank-one E-string theory saturates the universal lower
bound on , and numerically determine the spectrum of long multiplets in
the rank-one E-string theory. We comment on the possibility of solving the
higher-rank E-string theories by bootstrap and thereby probing M-theory on
AdS/.Comment: 59 pages, 10 figures, 4 tables; v2-v5: typos corrected, references
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Regulatory Change and Micro Structure Effects in SPI Futures
In this article we investigate and test for structural change in conditional volatility and micro structure effects in the Australian Share Price Index futures contract. The modelling is conducted around the periods following the introduction of an automated screen-based trading system and alterations to the trading day. Multiple point Switching GARCH models are employed following a detailed examination of conditional volatility, volume and maturity features. The data is sampled at 5, 15 and 30-minute intervals from transaction records supplied by the Sydney Futures Exchange. Micro-structure features that are found to be important in the preliminary analysis are incorporated in the formal models. Failure to test for and then account for any of these market features would imply that tests for structural changes are mis-specified. There is significant evidence of structural changes in both the persistence of volatility shocks and simultaneous volume effects following the change to screen trading in this futures market.Regulatory intervention, Structural Breaks, Micro Structure Effects.
On Path Memory in List Successive Cancellation Decoder of Polar Codes
Polar code is a breakthrough in coding theory. Using list successive
cancellation decoding with large list size L, polar codes can achieve excellent
error correction performance. The L partial decoded vectors are stored in the
path memory and updated according to the results of list management. In the
state-of-the-art designs, the memories are implemented with registers and a
large crossbar is used for copying the partial decoded vectors from one block
of memory to another during the update. The architectures are quite area-costly
when the code length and list size are large. To solve this problem, we propose
two optimization schemes for the path memory in this work. First, a folded path
memory architecture is presented to reduce the area cost. Second, we show a
scheme that the path memory can be totally removed from the architecture.
Experimental results show that these schemes effectively reduce the area of
path memory.Comment: 5 pages, 6 figures, 2 table
Covariance Adjustments in Discrimination of Mixed Discrete and Continuous Variables
Sufficient conditions are given to ensure a better performance of the plug-in version of the covariates adjusted location linear discriminant function in an asymptotic comparison of the overall expected error rate. Our findings generalize several earlier results on discriminant function with covariance
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