9,426 research outputs found
Size Ramsey Numbers Involving Double Stars and Brooms
The topics of this thesis lie in graph Ramsey theory. Given two graphs G and H, by the Ramsey theorem, there exist infinitely many graphs F such that if we partition the edges of F into two sets, say Red and Blue, then either the graph induced by the red edges contains G or the graph induced by the blue edges contains H. The minimum order of F is called the Ramsey number and the minimum of the size of F is called the size Ramsey number. They are denoted by r(G, H) and ˆr(G, H), respectively. We will investigate size Ramsey numbers involving double stars and brooms
Temperature Dependence of the Effective Bag Constant and the Radius of a Nucleon in the Global Color Symmetry Model of QCD
We study the temperature dependence of the effective bag constant, the mass,
and the radius of a nucleon in the formalism of the simple global color
symmetry model in the Dyson-Schwinger equation approach of QCD with a
Gaussian-type effective gluon propagator. We obtain that, as the temperature is
lower than a critical value, the effective bag constant and the mass decrease
and the radius increases with the temperature increasing. As the critical
temperature is reached, the effective bag constant and the mass vanish and the
radius tends to infinity. At the same time, the chiral quark condensate
disappears. These phenomena indicate that the deconfinement and the chiral
symmetry restoration phase transitions can take place at high temperature. The
dependence of the critical temperature on the interaction strength parameter in
the effective gluon propagator of the approach is given.Comment: 10 pages, 9 figure
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
Deshkan Ziibi Conservation Impact Bond Replication
Description of the work that I did the summer and its respective outcomes
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