16,734 research outputs found
The Schwinger Model on a circle: relation between Path Integral and Hamiltonian approaches
We solve the massless Schwinger model exactly in Hamiltonian formalism on a
circle. We construct physical states explicitly and discuss the role of the
spectral flow and nonperturbative vacua. Different thermodynamical correlation
functions are calculated and after performing the analytical continuation are
compared with the corresponding expressions obtained for the Schwinger model on
the torus in Euclidean Path Integral formalism obtained before.Comment: 40 page
A note on the peeling theorem in higher dimensions
We demonstrate the ``peeling property'' of the Weyl tensor in higher
dimensions in the case of even dimensions (and with some additional
assumptions), thereby providing a first step towards understanding of the
general peeling behaviour of the Weyl tensor, and the asymptotic structure at
null infinity, in higher dimensions.Comment: 5 pages, to appear in Class. Quantum Gra
Nonparametric Transient Classification using Adaptive Wavelets
Classifying transients based on multi band light curves is a challenging but
crucial problem in the era of GAIA and LSST since the sheer volume of
transients will make spectroscopic classification unfeasible. Here we present a
nonparametric classifier that uses the transient's light curve measurements to
predict its class given training data. It implements two novel components: the
first is the use of the BAGIDIS wavelet methodology - a characterization of
functional data using hierarchical wavelet coefficients. The second novelty is
the introduction of a ranked probability classifier on the wavelet coefficients
that handles both the heteroscedasticity of the data in addition to the
potential non-representativity of the training set. The ranked classifier is
simple and quick to implement while a major advantage of the BAGIDIS wavelets
is that they are translation invariant, hence they do not need the light curves
to be aligned to extract features. Further, BAGIDIS is nonparametric so it can
be used for blind searches for new objects. We demonstrate the effectiveness of
our ranked wavelet classifier against the well-tested Supernova Photometric
Classification Challenge dataset in which the challenge is to correctly
classify light curves as Type Ia or non-Ia supernovae. We train our ranked
probability classifier on the spectroscopically-confirmed subsample (which is
not representative) and show that it gives good results for all supernova with
observed light curve timespans greater than 100 days (roughly 55% of the
dataset). For such data, we obtain a Ia efficiency of 80.5% and a purity of
82.4% yielding a highly competitive score of 0.49 whilst implementing a truly
"model-blind" approach to supernova classification. Consequently this approach
may be particularly suitable for the classification of astronomical transients
in the era of large synoptic sky surveys.Comment: 14 pages, 8 figures. Published in MNRA
Survival As An Implied Condition In A Contingent Gift To A Class - The Demill Rule Revisited - Second Bank-State Street Trust Company v. Weston
Economic Consequences of Health Status: A Review of the Evidence
The correlation between health and economic performance is extremely robust across communities and over time. Many factors exogenous to income play an important role in determining health status, including a number of geographical, environmental, and evolutionary factors. This suggests the existence of simultaneous impacts of health on wealth and wealth on health. Potential health impacts on national economic performance are explored, and some important unanswered questions are identified.health, economic growth, human capital
Older Adults and Forgoing Cancer Screening
Although there is a growing recognition that older adults and those with extensive comorbid conditions undergo cancer screening too frequently, there is little information about patients’ perceptions regarding cessation of cancer screening. Information on older adults’ views of screening cessation would be helpful both for clinicians and for those designing interventions to reduce overscreening
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