2,907 research outputs found
Bound on Lorentz- and CPT-Violating Boost Effects for the Neutron
A search for an annual variation of a daily sidereal modulation of the
frequency difference between co-located Xe and He Zeeman
masers sets a stringent limit on boost-dependent Lorentz and CPT violation
involving the neutron, consistent with no effect at the level of 150 nHz. In
the framework of the general Standard-Model Extension, the present result
provides the first clean test for the fermion sector of the symmetry of
spacetime under boost transformations at a level of GeV.Comment: 4 pages, 1 figur
A Few Signatories for the Proposal for an Association of Law Teachers
Letters from several professors who agreed to be signatories for the proposal for an association of law teachers
Sparse Randomized Kaczmarz for Support Recovery of Jointly Sparse Corrupted Multiple Measurement Vectors
While single measurement vector (SMV) models have been widely studied in
signal processing, there is a surging interest in addressing the multiple
measurement vectors (MMV) problem. In the MMV setting, more than one
measurement vector is available and the multiple signals to be recovered share
some commonalities such as a common support. Applications in which MMV is a
naturally occurring phenomenon include online streaming, medical imaging, and
video recovery. This work presents a stochastic iterative algorithm for the
support recovery of jointly sparse corrupted MMV. We present a variant of the
Sparse Randomized Kaczmarz algorithm for corrupted MMV and compare our proposed
method with an existing Kaczmarz type algorithm for MMV problems. We also
showcase the usefulness of our approach in the online (streaming) setting and
provide empirical evidence that suggests the robustness of the proposed method
to the distribution of the corruption and the number of corruptions occurring.Comment: 13 pages, 6 figure
Polygraphic Variations in Reactivity Between Delusional, Non-Delusional, and Control Groups in a Crime Situation
Polygraphic Variations in Reactivity Between Delusional, Non-Delusional, and Control Groups in a Crime Situation
f(R) actions, cosmic acceleration and local tests of gravity
We study spherically symmetric solutions in f(R) theories and its
compatibility with local tests of gravity. We start by clarifying the range of
validity of the weak field expansion and show that for many models proposed to
address the Dark Energy problem this expansion breaks down in realistic
situations. This invalidates the conclusions of several papers that make
inappropriate use of this expansion. For the stable models that modify gravity
only at small curvatures we find that when the asymptotic background curvature
is large we approximately recover the solutions of Einstein gravity through the
so-called Chameleon mechanism, as a result of the non-linear dynamics of the
extra scalar degree of freedom contained in the metric. In these models one
would observe a transition from Einstein to scalar-tensor gravity as the
Universe expands and the background curvature diminishes. Assuming an adiabatic
evolution we estimate the redshift at which this transition would take place
for a source with given mass and radius. We also show that models of dynamical
Dark Energy claimed to be compatible with tests of gravity because the mass of
the scalar is large in vacuum (e.g. those that also include R^2 corrections in
the action), are not viable.Comment: 26 page
Harmonic Analysis of Boolean Networks: Determinative Power and Perturbations
Consider a large Boolean network with a feed forward structure. Given a
probability distribution on the inputs, can one find, possibly small,
collections of input nodes that determine the states of most other nodes in the
network? To answer this question, a notion that quantifies the determinative
power of an input over the states of the nodes in the network is needed. We
argue that the mutual information (MI) between a given subset of the inputs X =
{X_1, ..., X_n} of some node i and its associated function f_i(X) quantifies
the determinative power of this set of inputs over node i. We compare the
determinative power of a set of inputs to the sensitivity to perturbations to
these inputs, and find that, maybe surprisingly, an input that has large
sensitivity to perturbations does not necessarily have large determinative
power. However, for unate functions, which play an important role in genetic
regulatory networks, we find a direct relation between MI and sensitivity to
perturbations. As an application of our results, we analyze the large-scale
regulatory network of Escherichia coli. We identify the most determinative
nodes and show that a small subset of those reduces the overall uncertainty of
the network state significantly. Furthermore, the network is found to be
tolerant to perturbations of its inputs
Starting Strong: Talent-Based Branching of Newly Commissioned U.S. Army Officers
Because the U.S. military\u27s long-held advantage in physical capital and equipment is waning, cutting-edge human capital management is more critical than ever before. The authors of Starting Strong argue that by gathering detailed information on the unique talents possessed by each newly commissioned Army officer, as well as on the unique talent demands of each Army basic branch, the Army can create a talent market that identifies and liberates the strengths of every officer, aligning each with the career field where they are most likely to be engaged, productive, and satisfied leaders. Strong evidence demonstrates that this talent-based approach better aligns officer talent with occupational requirements while simultaneously increasing individual branch satisfaction.https://press.armywarcollege.edu/monographs/1423/thumbnail.jp
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