4,843 research outputs found
Aspects of Confinement and Chiral Dynamics in 2-d QED at Finite Temperature
We evaluate the Polyakov loop and string tension at zero and finite
temperature in Using bozonization the problem is reduced to solving
the Schr\"odinger equation with a particular potential determined by the ground
state. In the presence of two sources of opposite charges the vacuum angle
parameter changes by , independent of the number of
flavors. This, in turn, alters the chiral condensate. Particularly, in the one
flavor case through a simple computer algorithm, we explore the chiral dynamics
of a heavy fermion.Comment: 4 pages, 2 ps files, uses sprocl.sty. To appear in Proceedings of
DPF96 (August, Minnesota
Confinement and Chiral Dynamics in the Multi-flavor Schwinger Model
Two-dimensional QED with flavor fermions is solved at zero and finite
temperature with arbitrary fermion masses to explore QCD physics such as chiral
condensate and string tension. The problem is reduced to solving a
Schr\"odinger equation for degrees of freedom with a specific potential
determined by the ground state of the Schr\"odinger problem itself.Comment: 9 pages. 3 ps files and sprocl.sty attached. To appear in the
Proceedings of the QCD 96 workshop (March, Minnesota
Improving the communication with stakeholders: the infrastructure degradation index and the infrastructure histogram
[EN] Water infrastructures are rapidly ageing without being properly replaced. Communicating the state of the network and the sector¿s needs to stakeholders is key for guaranteeing the sustainability of water and sewage systems. The infrastructure value index (IVI) is becoming a standard in the water industry as a communication tool; however, as a single value metric, it can mask key information. The complementary use of the infrastructure degradation index (IDI) and the infrastructure histogram (Hi) can provide a better understanding of the network's state while maintaining the simplicity of the analysis needed for public dissemination. The IVI is focused on the value of the infrastructure, the IDI on its median remaining life. The HI provides a detailed but simple picture of the network's remaining life, providing a clear idea of the magnitude of the investments needed in the future for maintaining the infrastructureEstruch-Juan, ME.; Cabrera Rochera, E.; Gomez Selles, E.; Del Teso-March, R. (2020). Improving the communication with stakeholders: the infrastructure degradation index and the infrastructure histogram. Water Science & Technology: Water Supply. 20(7):2762-2767. https://doi.org/10.2166/ws.2020.170S2762276720
Anomalies, Horizons and Hawking radiation
Hawking radiation is obtained from the Reissner-Nordstr\"{o}m blackhole with
a global monopole and the Garfinkle-Horowitz-Strominger blackhole falling in
the class of the most general spherically symmetric blackholes
, using only chiral anomaly near the event horizon and
covariant boundary condition at the event horizon. The approach differs from
the anomaly cancellation approach since apart from the covariant boundary
condition, the chiral anomaly near the horizon is the only input to derive the
Hawking flux.Comment: minor corrections made, To appear in Euro. Phys. Letter
Hawking Radiation from Charged Black Holes via Gauge and Gravitational Anomalies
Extending gr-qc/0502074, we show that in order to avoid a breakdown of
general covariance and gauge invariance at the quantum level the total flux of
charge and energy in each outgoing partial wave of a charged quantum field in a
Reissner-Nordstrom black hole background must be equal to that of a (1+1)
dimensional blackbody at the Hawking temperature with the appropriate chemical
potential.Comment: 4 pages, typos corrected, references added, version to appear in
Phys. Rev. Let
Standardisation of magnetic nanoparticles in liquid suspension
Suspensions of magnetic nanoparticles offer diverse opportunities for technology innovation, spanning a large number of industry sectors from imaging and actuation based applications in biomedicine and biotechnology, through large-scale environmental remediation uses such as water purification, to engineering-based applications such as position-controlled lubricants and soaps. Continuous advances in their manufacture have produced an ever-growing range of products, each with their own unique properties. At the same time, the characterisation of magnetic nanoparticles is often complex, and expert knowledge is needed to correctly interpret the measurement data. In many cases, the stringent requirements of the end-user technologies dictate that magnetic nanoparticle products should be clearly defined, well characterised, consistent and safe; or to put it another way—standardised. The aims of this document are to outline the concepts and terminology necessary for discussion of magnetic nanoparticles, to examine the current state-of-the-art in characterisation methods necessary for the most prominent applications of magnetic nanoparticle suspensions, to suggest a possible structure for the future development of standardisation within the field, and to identify areas and topics which deserve to be the focus of future work items. We discuss potential roadmaps for the future standardisation of this developing industry, and the likely challenges to be encountered along the way
Chern-Simons matrix model: coherent states and relation to Laughlin wavefunctions
Using a coherent state representation we derive many-body probability
distributions and wavefunctions for the Chern-Simons matrix model proposed by
Polychronakos and compare them to the Laughlin ones. We analyze two different
coherent state representations, corresponding to different choices for electron
coordinate bases. In both cases we find that the resulting probability
distributions do not quite agree with the Laughlin ones. There is agreement on
the long distance behavior, but the short distance behavior is different.Comment: 15 pages, LaTeX; one reference added, abstract and section 5
expanded, typos correcte
Back reaction, covariant anomaly and effective action
In the presence of back reaction, we first produce the one-loop corrections
for the event horizon and Hawking temperature of the Reissner-Nordstr\"om black
hole. Then, based on the covariant anomaly cancelation method and the effective
action technique, the modified expressions for the fluxes of gauge current and
energy momentum tensor, due to the effect of back reaction, are obtained. The
results are consistent with the Hawking fluxes of a (1+1)-dimensional blackbody
at the temperature with quantum corrections, thus confirming the robustness of
the covariant anomaly cancelation method and the effective action technique for
black holes with back reaction.Comment: 17 page
Microscopic Theory of Skyrmions in Quantum Hall Ferromagnets
We present a microscopic theory of skyrmions in the monolayer quantum Hall
ferromagnet. It is a peculiar feature of the system that the number density and
the spin density are entangled intrinsically as dictated by the W
algebra. The skyrmion and antiskyrmion states are constructed as W-rotated states of the hole-excited and electron-excited states,
respectively. They are spin textures accompanied with density modulation that
decreases the Coulomb energy. We calculate their excitation energy as a
function of the Zeeman gap and compared the result with experimental data.Comment: 15 pages (to be published in PRB
Hawking Fluxes, Back reaction and Covariant Anomalies
Starting from the chiral covariant effective action approach of Banerjee and
Kulkarni [Phys. Lett. B 659, 827(2008)], we provide a derivation of the Hawking
radiation from a charged black hole in the presence of gravitational back
reaction. The modified expressions for charge and energy flux, due to effect of
one loop back reaction are obtained.Comment: 6 pages, no figures, minor changes and references added, to appear in
Classical and Quantum Gravit
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