9,988 research outputs found
Spontaneous electromagnetic superconductivity and superfluidity of QCDxQED vacuum in strong magnetic field
It was recently shown that the vacuum in the background of a strong enough
magnetic field may become an electromagnetic superconductor due to interplay
between strong and electromagnetic forces. The superconducting ground state of
the QCDxQED sector of the vacuum is associated with magnetic-field-assisted
emergence of quark-antiquark condensates which carry quantum numbers of charged
rho mesons (i.e., of electrically charged vector particles made of lightest, u
and d, quarks and antiquarks). Here we demonstrate that this exotic
electromagnetic superconductivity of vacuum is also accompanied by even more
exotic superfluidity of the neutral rho mesons. The superfluid component --
despite being electrically neutral -- turns out to be sensitive to an external
electric field as the superfluid may ballistically be accelerated by a test
background electric field along the magnetic-field axis. In the ground state
both superconducting and superfluid components are inhomogeneous periodic
functions of the transversal (with respect to the axis of the magnetic field)
spatial coordinates. The superconducting part of the ground state resembles an
Abrikosov ground state in a type-II superconductor: the superconducting
condensate organizes itself in periodic structure which possesses the symmetry
of an equilateral triangular lattice. Each elementary lattice cell contains a
stringlike topological defect (superconductor vortex) in the charged rho
condensates as well as three superfluid vortices and three superfluid
antivortices made of the neutral rho condensate. The superposition of the
superconductor and superfluid vortex lattices has a complicated "kaleidoscopic"
pattern.Comment: 6 pages, 2 figures. Talk given at Sixth International Conference on
Quarks and Nuclear Physics QNP2012, April 16-20, 2012, Ecole Polytechnique,
Palaiseau, Franc
Phonon spectrum of QCD vacuum in magnetic-field-induced superconducting phase
In the background of a sufficiently strong magnetic field the vacuum was
suggested to become an ideal electric conductor (highly anisotropic
superconductor) due to an interplay between the strong and electromagnetic
forces. The superconducting ground state resembles an Abrikosov lattice state
in an ordinary type--II superconductor: it is an inhomogeneous structure made
of a (charged vector) quark-antiquark condensate pierced by vortices. In this
paper the acoustic (phonon) vibrational modes of the vortex lattice are studied
at zero temperature. Using an effective model based on a vector meson
dominance, we show that in the infrared limit the longitudinal (transverse)
acoustic vibrations of the vortex lattice possess a linear (quadratic)
dispersion relation corresponding to type I (type II) Nambu--Goldstone modes.Comment: 12 pages, 3 figures; v2: minor changes, published versio
That\u27s the Tune They Play in Dixie Land (My Home Sweet Home)
https://digitalcommons.library.umaine.edu/mmb-vp/6551/thumbnail.jp
When a Fellow Has A Sweethear, Life\u27s a Song
https://digitalcommons.library.umaine.edu/mmb-vp/5754/thumbnail.jp
If You Are No One\u27s Sweetheart : Is There Any Chance for Me?
https://digitalcommons.library.umaine.edu/mmb-vp/1822/thumbnail.jp
Somewhere there is Someone I\u27d like to know
https://digitalcommons.library.umaine.edu/mmb-vp/6181/thumbnail.jp
Seeking out and building monopolies, Rothschild strategies in non ferrous metals international markets (1830-1940)
The aim of this article is to analyse the strategies employed by the Rothschilds until 1940 to limit competition in the non ferrous international market. We will study how they opted for rigid demand products of highly concentrated supply which were favourable to market control (mercury, nickel, lead and copper and sulphur) by assuming administrative monopolies (mercury from Spanish Almadn Mines) or through control of the leading businesses of the respective markets (Le Nickel, Pearroya and Rio Tinto). We will also analyse how the family was able to gain worldwide monopolies, or if not, how they promoted collusive oligopolies with the competition in any number of forms in their quest to maintain profitability and to flee from any competition.International Raw material markets, Cartels, Rothschild, mining, Non-ferrous metals.
Reactive Turing Machines
We propose reactive Turing machines (RTMs), extending classical Turing
machines with a process-theoretical notion of interaction, and use it to define
a notion of executable transition system. We show that every computable
transition system with a bounded branching degree is simulated modulo
divergence-preserving branching bisimilarity by an RTM, and that every
effective transition system is simulated modulo the variant of branching
bisimilarity that does not require divergence preservation. We conclude from
these results that the parallel composition of (communicating) RTMs can be
simulated by a single RTM. We prove that there exist universal RTMs modulo
branching bisimilarity, but these essentially employ divergence to be able to
simulate an RTM of arbitrary branching degree. We also prove that modulo
divergence-preserving branching bisimilarity there are RTMs that are universal
up to their own branching degree. Finally, we establish a correspondence
between executability and finite definability in a simple process calculus
Electronic fraud detection in the U.S. Medicaid Healthcare Program: lessons learned from other industries
It is estimated that between 850 billion annually is lost to fraud, waste, and abuse in the US healthcare system,with 175 billion of this due to fraudulent activity (Kelley 2009). Medicaid, a state-run, federally-matchedgovernment program which accounts for roughly one-quarter of all healthcare expenses in the US, has been particularlysusceptible targets for fraud in recent years. With escalating overall healthcare costs, payers, especially government-runprograms, must seek savings throughout the system to maintain reasonable quality of care standards. As such, the need foreffective fraud detection and prevention is critical. Electronic fraud detection systems are widely used in the insurance,telecommunications, and financial sectors. What lessons can be learned from these efforts and applied to improve frauddetection in the Medicaid health care program? In this paper, we conduct a systematic literature study to analyze theapplicability of existing electronic fraud detection techniques in similar industries to the US Medicaid program
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