1,359 research outputs found
The role of field redefinition on renormalisability of a general supersymmetric gauge theories
We investigate some issues on renormalisability of non-anticommutative
supersymmetric gauge theory related to field redefinitions. We study one loop
corrections to supersymmetric gauge theory
coupled to chiral matter in component formalism, and show the procedure which
has been introduced for renormalisation is problematic because some terms which
are needed for the renormalisability of theory are missed from the Lagrangian.
In order to prove the theory is renormalisable, we redefine the gaugino and the
auxiliary fields(), which result in a modified form of the
Lagrangian in the component formalism. Then, we show the modified Lagrangian
has extra terms which are necessary for renormalisability of
non-anticommutative supersymmetric gauge field theories. Finally we prove supersymmetric gauge theory is renormalisable up to one loop
corrections using standard method of renormalisation; besides, it is shown the
effective action is gauge invariant.Comment: arXiv admin note: text overlap with arXiv:hep-th/0505248 by other
author
Towards Informative Statistical Flow Inversion
This is the accepted version of 'Towards Informative Statistical Flow Inversion', archived originally at arXiv:0705.1939v1 [cs.NI] 14 May 2007.A problem which has recently attracted research attention is that of estimating the distribution of flow sizes in internet traffic. On high traffic links it is sometimes impossible to record every packet. Researchers have approached the problem of estimating flow lengths from sampled packet data in two separate ways. Firstly, different sampling methodologies can be tried to more accurately measure the desired system parameters. One such method is the sample-and-hold method where, if a packet is sampled, all subsequent packets in that flow are sampled. Secondly, statistical methods can be used to ``invert'' the sampled data and produce an estimate of flow lengths from a sample. In this paper we propose, implement and test two variants on the sample-and-hold method. In addition we show how the sample-and-hold method can be inverted to get an estimation of the genuine distribution of flow sizes. Experiments are carried out on real network traces to compare standard packet sampling with three variants of sample-and-hold. The methods are compared for their ability to reconstruct the genuine distribution of flow sizes in the traffic
Some algebraic properties of fuzzy S-acts
S-acts, a useful and important algebraic tool, have always been interest to mathematicians, specially to computer scientists. When A. Zadeh introduced the notion of the fuzzy subset in 1965, his idea opened a new direction to reserchers to provide tools in the various elds of mathematics. Here we are going to investigate some algebraic properties of fuzzy S-acts. We rst make an S-act from the fuzzy sub-sets of an S-act A. Then we use this tool to give a characterization for fuzzy S-acts. We then introduce the notion of generated fuzzy S-act by a fuzzy subset of an S-act and give a characterization for the fuzzy actions. And then we dene the notion of indecomposable fuzzy S-act and nd some indecomposable fuzzy actions
Transverse expansion of hot magnetized Bjorken flow in heavy ion collisions
We argue that the existence of an inhomogeneous external magnetic field can
lead to radial flow in transverse plane. Our aim is to show how the
introduction of a magnetic field generalizes the Bjorken flow. We investigate
the effect of an inhomogeneous weak external magnetic field on the transverse
expansion of in-viscid fluid created in high energy nuclear collisions. In
order to simplify our calculation and compare with Gubser model, we consider
the fluid under investigation to be produced in central collisions, at small
impact parameter; azimuthal symmetry has been considered. In our model, we
assume an inhomogeneous external magnetic field following the power-law decay
in proper time and having radial inhomogeneity perpendicular to the radial
velocity of the in-viscid fluid in the transverse plane; then the space time
evolution of the transverse expansion of the fluid is obtained. We also show
how the existence of an inhomogeneous external magnetic field modifies the
energy density. Finally we use the solutions for the transverse velocity and
energy density in the presence of a weak magnetic field, to estimate the
transverse momentum spectrum of protons and pions emerging from the
Magneto-hydrodynamic solutions
Non-relativistic approximate numerical ideal-magneto hydrodynamics of (1+1) D transverse flow in Bjorken scenario
In this study, we investigate the impact of the magnetic field on the
evolution of the transverse flow of QGP matter in the magneto-hydrodynamic
(MHD) framework. We assume that the magnetic field is perpendicular to the
reaction plane and then we solve the coupled Maxwell and conservation equations
in (1+1D) transverse flow, within the Bjorken scenario. We consider a QGP with
infinite electrical conductivity. First, the magnetic effects on the QGP medium
at mid-rapidity are investigated at leading order; then the time and space
dependence of the energy density, velocity and magnetic field in the transverse
plane of the ideal magnetized hot plasma are obtained
The spread of media content through blogs
Blogs are a popular way to share personal journals, discuss matters of public opinion, pursue collaborative conversations, and aggregate content on similar topics. Blogs can be also used to disseminate new content and novel ideas to communities of interest. In this paper, we present an analysis of the topological structure and the patterns of popular media content that is shared in blogs. By analyzing 8.7 million posts of 1.1 million blogs across 15 major blog hosting sites, we find that the network structure of blogs is “less social” compared to other online social networks: most links are unidirectional and the network is sparsely connected. The type of content that was popularly shared on blogs was surprisingly different from that from the mainstream media: user generated content, often in the form of videos or photos, was the most common type of content disseminated in blogs. The user-generated content showed interesting viral-spreading patterns within blogs. Topical content such as news and political commentary spreads quickly by the hour and then quickly disappears, while non-topical content such as music and entertainment propagates slowly over a much long period of time
Beyond Node Degree: Evaluating AS Topology Models
This is the accepted version of 'Beyond Node Degree: Evaluating AS Topology Models', archived originally at arXiv:0807.2023v1 [cs.NI] 13 July 2008.Many models have been proposed to generate Internet Autonomous System (AS) topologies, most of which make structural assumptions about the AS graph. In this paper we compare AS topology generation models with several observed AS topologies. In contrast to most previous works, we avoid making assumptions about which topological properties are important to characterize the AS topology. Our analysis shows that, although matching degree-based properties, the existing AS topology generation models fail to capture the complexity of the local interconnection structure between ASs. Furthermore, we use BGP data from multiple vantage points to show that additional measurement locations significantly affect local structure properties, such as clustering and node centrality. Degree-based properties, however, are not notably affected by additional measurements locations. These observations are particularly valid in the core. The shortcomings of AS topology generation models stems from an underestimation of the complexity of the connectivity in the core caused by inappropriate use of BGP data
The category {\bf Rel}({\bf Nom})
The category may be formed for any category
with finite limits using the same objects as but
whose morphisms from to are binary relations in , that is,
subobjects of . In this paper, concerning the topos , we
study the category . In this category, we define and
investigate certain morphisms, such as deterministic morphisms.
Then, stochastic mappings between nominal sets are defined by exploiting the
underlying relation of functions between nominal sets. This allows one to
reinterpret concepts and earlier results in terms of morphisms
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