8,046 research outputs found
Propagation of ultrahigh-energy neutrinos through the Earth
The dispersion relation in matter of ultrahigh-energy neutrinos above the
pole of the resonance (E_{\nu} \gsim {\rm 10}^{7} {\rm GeV} ), is
studied. We perform our calculation using the real-time formulation of Thermal
Field Theory in which the massless limit for the boson is taken. The range
of active-to-sterile neutrino oscillation parameters for which there is
significant mixing enhancement during propagation through the interior of the
Earth, and therefore significant attenuation of neutrino beams in the Earth at
high energies, is estimated. Finally, this range is considered in view of the
cosmological and astrophysical constraints.Comment: 8 pages, some comments and references added, to appear in Phys. Lett.
Disciplining Voluntary Environmental Standards At The WTO - An Indian Legal Viewpoint
This paper looks into the proliferation of privately-formulated environmental product standards and analyses whether Indian industry has a legal recourse under the WTO dispute settlement mechanism if such standards are used as disguised restrictions on trade. The paper highlights some of the issues faced by Indian manufacturers when confronted with voluntary product requirements such as eco-labeling, packaging and recycling requirements in markets of key export interest to them and highlights the role of non-state actors in the formulation of such environmental product standards. Since some of these product standards are capable of being misused as protectionist devices, the paper examines whether the WTO dispute settlement mechanism can be used to resolve an issue which cannot be directly attributed to governmental action (or inaction). In doing so the paper studies the representations made by India and other developing countries at meetings of various WTO Committees; and past decisions of WTO Panels and the Appellate Body to establish the magnitude of the problem and look for possible legal solutions. The paper looks at the issue from a developing country perspective- the assumption being that developing countries are standard-takers, not standard-setters; and are unable to afford the costs of compliance associated with voluntary environmental standards. The analysis focuses predominantly on the use and interpretation of the GATT Agreement and the Agreement on Technical Barriers to Trade and discusses a possible legal strategy that may be adopted in any future dispute.India, Environment, Law, Voluntary Environmental Standards
A Review of the Role of Melatonin in Irritable Bowel Syndrome
Irritable bowel syndrome (IBS) is a troubling disease experienced worldwide. The presentation of symptoms varies from patient to patient, and current prescription treatments can be inadequate in resolving symptoms. This article explores the available scientific literature supporting the use of melatonin in alleviating IBS symptoms
Jets and Jet Multiplicities in High Energy Photon-Nucleon Inetraction:
We discuss the theory of jet events in high-energy photon-proton interactions
using a model which gives a good description of the data available on total
inelastic cross sections up to =210 GeV. We show how to
calculate the jet cross sections and jet multiplicities and give predictions
for these quantities for energies appropriate for experiments at the HERA
collider and for very high energy cosmic ray observations.Comment: 12 pages + 4 figs, MAD/TH/92-8, submitted to Phys. Rev. D(Rapid
Communications), figs. available on request from [email protected]
Improved Approximation Algorithms for Stochastic Matching
In this paper we consider the Stochastic Matching problem, which is motivated
by applications in kidney exchange and online dating. We are given an
undirected graph in which every edge is assigned a probability of existence and
a positive profit, and each node is assigned a positive integer called timeout.
We know whether an edge exists or not only after probing it. On this random
graph we are executing a process, which one-by-one probes the edges and
gradually constructs a matching. The process is constrained in two ways: once
an edge is taken it cannot be removed from the matching, and the timeout of
node upper-bounds the number of edges incident to that can be probed.
The goal is to maximize the expected profit of the constructed matching.
For this problem Bansal et al. (Algorithmica 2012) provided a
-approximation algorithm for bipartite graphs, and a -approximation for
general graphs. In this work we improve the approximation factors to
and , respectively.
We also consider an online version of the bipartite case, where one side of
the partition arrives node by node, and each time a node arrives we have to
decide which edges incident to we want to probe, and in which order. Here
we present a -approximation, improving on the -approximation of
Bansal et al.
The main technical ingredient in our result is a novel way of probing edges
according to a random but non-uniform permutation. Patching this method with an
algorithm that works best for large probability edges (plus some additional
ideas) leads to our improved approximation factors
- …