27,126 research outputs found
Future Developments in Low Temperature Detectors for CMB and Submm Astronomy
We summarize the wide range of current and upcoming developments in low temperature detectors for CMB and submillimeter astronomy. We discuss work in sensor development, photon coupling and filtering architectures, and polarimetry and how these tie to applications requirements
Constant Scalar Curvature Metrics on Boundary Complexes of Cyclic Polytopes
In [7], a notion of constant scalar curvature metrics on piecewise flat
manifolds is defined. Such metrics are candidates for canonical metrics on
discrete manifolds. In this paper, we define a class of vertex transitive
metrics on certain triangulations of ; namely, the boundary
complexes of cyclic polytopes. We use combinatorial properties of cyclic
polytopes to show that, for any number of vertices, these metrics have constant
scalar curvature.Comment: 15 pages, 4 figure
A Symplectic Test of the L-Functions Ratios Conjecture
Recently Conrey, Farmer and Zirnbauer conjectured formulas for the averages
over a family of ratios of products of shifted L-functions. Their L-functions
Ratios Conjecture predicts both the main and lower order terms for many
problems, ranging from n-level correlations and densities to mollifiers and
moments to vanishing at the central point. There are now many results showing
agreement between the main terms of number theory and random matrix theory;
however, there are very few families where the lower order terms are known.
These terms often depend on subtle arithmetic properties of the family, and
provide a way to break the universality of behavior. The L-functions Ratios
Conjecture provides a powerful and tractable way to predict these terms. We
test a specific case here, that of the 1-level density for the symplectic
family of quadratic Dirichlet characters arising from even fundamental
discriminants d \le X. For test functions supported in (-1/3, 1/3) we calculate
all the lower order terms up to size O(X^{-1/2+epsilon}) and observe perfect
agreement with the conjecture (for test functions supported in (-1, 1) we show
agreement up to errors of size O(X^{-epsilon}) for any epsilon). Thus for this
family and suitably restricted test functions, we completely verify the Ratios
Conjecture's prediction for the 1-level density.Comment: 29 pages, version 1.3 (corrected a typo in the proof of Lemma 3.2 and
a few other typos, updated some references). To appear in IMR
Strangeness contributions to nucleon form factors
We review a recent theoretical determination of the strange quark content of
the electromagnetic form factors of the nucleon. These are compared with a
global analysis of current experimental measurements in parity-violating
electron scattering.Comment: 5 pages, 6 figures; Talk presented at the International Workshop
"From Parity Violation to Hadronic Structure and more...", Milos, Greece, May
16-20, 200
Systematic uncertainties in the precise determination of the strangeness magnetic moment of the nucleon
Systematic uncertainties in the recent precise determination of the
strangeness magnetic moment of the nucleon are identified and quantified. In
summary, G_M^s = -0.046 \pm 0.019 \mu_N.Comment: Invited presentation at PAVI '04, International Workshop on Parity
Violation and Hadronic Structure, Laboratoire de Physique Subatomique et de
Cosmologie, Grenoble, France, June 8-11, 2004. 7 pages, 16 figure
Moments of the critical values of families of elliptic curves, with applications
We make conjectures on the moments of the central values of the family of all
elliptic curves and on the moments of the first derivative of the central
values of a large family of positive rank curves. In both cases the order of
magnitude is the same as that of the moments of the central values of an
orthogonal family of L-functions. Notably, we predict that the critical values
of all rank 1 elliptic curves is logarithmically larger than the rank 1 curves
in the positive rank family.
Furthermore, as arithmetical applications we make a conjecture on the
distribution of a_p's amongst all rank 2 elliptic curves, and also show how the
Riemann hypothesis can be deduced from sufficient knowledge of the first moment
of the positive rank family (based on an idea of Iwaniec).Comment: 24 page
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