7,246 research outputs found
Cancellation of divergences in unitary gauge calculation of process via one W loop, and application
Following the thread of R. Gastmans, S. L. Wu and T. T. Wu, the calculation
in the unitary gauge for the process via one W loop is
repeated, without the specific choice of the independent integrated loop
momentum at the beginning. We start from the 'original' definition of each
Feynman diagram, and show that the 4-momentum conservation and the Ward
identity of the W-W-photon vertex can guarantee the cancellation of all terms
among the Feynman diagrams which are to be integrated to give divergences
higher than logarithmic. The remaining terms are to the most logarithmically
divergent, hence is independent from the set of integrated loop momentum. This
way of doing calculation is applied to process via one W loop
in the unitary gauge, the divergences proportional to including
quadratic ones are all cancelled, and terms proportional to are
shown to be zero. The way of dealing with the quadratic divergences
proportional to in has subtle implication on the
employment on the Feynman rules especially when those rules can lead to high
level divergences. So calculation without integration on all the
functions until have to is a more proper or maybe necessary way of the
employment of the Feynman rules.Comment: 1 figure, 34 pages (updated
Temperature-heat uncertainty relation for quantum thermometry
We investigate the resource theory for temperature estimation. We demonstrate
that it is the fluctuation of heat that fundamentally determines temperature
precision through the temperature-heat uncertainty relation. Specifically, we
find that heat is divided into trajectory heat and correlation heat, which are
associated with the heat exchange along thermometer's evolution path and the
correlation between the thermometer and the sample, respectively. Based on two
type of thermometers, we show that both of these heat terms are resources for
enhancing temperature precision. Additionally, we demonstrate that the
temperature-heat uncertainty relation is consistent with the well known
temperature-energy uncertainty relation in thermodynamics. By clearly
distinguishing the resources for enhancing estimation precision, our findings
not only explain why various quantum features are crucial for accurate
temperature sensing but also provide valuable insights for designing
ultrahigh-sensitive quantum thermometers.Comment: 6 pages, 1 figur
Lifshitz effects on holographic -wave superfluid
In the probe limit, we numerically build a holographic -wave superfluid
model in the four-dimensional Lifshitz black hole coupled to a Maxwell-complex
vector field. We observe the rich phase structure and find that the Lifshitz
dynamical exponent contributes evidently to the effective mass of the
matter field and dimension of the gravitational background. Concretely, we
obtain the Cave of Winds appeared only in the five-dimensional anti-de
Sitter~(AdS) spacetime, and the increasing hinders not only the condensate
but also the appearance of the first-order phase transition. Furthermore, our
results agree with the Ginzburg-Landau results near the critical temperature.
In addition, the previous AdS superfluid model is generalized to the Lifshitz
spacetime.Comment: 14 pages,5 figures, and 1 table, accepted by Phys. Lett.
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