5,283 research outputs found
Goldstone Modes in Renormalizable Supersymmetric SO(10) Model
We solve the Goldstone modes in the renormalizable SUSY SO(10) model with
general couplings. The Goldstones are expressed by the Vacuum Expectation
Values and the Clebsch-Gordan coefficients of relevant symmetries without
explicit dependence on the parameters of the model.Comment: 27 pages. Only arXiv number for [38] adde
Black hole evaporation based upon a q-deformation description
A toy model based upon the -deformation description for studying the
radiation spectrum of black hole is proposed. The starting point is to make an
attempt to consider the spacetime noncommutativity in the vicinity of black
hole horizon. We use a trick that all the spacetime noncommutative effects are
ascribed to the modification of the behavior of the radiation field of black
hole and a kind of q-deformed degrees of freedom are postulated to mimic the
radiation particles that live on the noncommutative spacetime, meanwhile the
background metric is preserved as usual. We calculate the radiation spectrum of
Schwarzschild black hole in this framework. The new distribution deviates from
the standard thermal spectrum evidently. The result indicates that some
correlation effect will be introduced to the system if the noncommutativity is
taken into account. In addition, an infrared cut-off of the spectrum is the
prediction of the model.Comment: 13 pages, 2 figure
Numerical Simulation of a Marine Current Turbine in Turbulent Flow
The copyright of this thesis rests with the author and no quotation from it or information derived from it may be published without the prior written consent of the authorThe marine current turbine (MCT) is an exciting proposition for the extraction of renewable tidal and marine current power. However, the numerical prediction of the performance of the MCT is difficult due to its complex geometry, the surrounding turbulent flow and the free surface. The main purpose of this research is to develop a computational tool for the simulation of a MCT in turbulent flow and in this thesis, the author has modified a 3D Large Eddy Simulation (LES) numerical code to simulate a three blade MCT under a variety of operating conditions based on the Immersed Boundary Method (IBM) and the Conservative Level Set Method (CLS).
The interaction between the solid structure and surrounding fluid is modelled by the immersed boundary method, which the author modified to handle the complex geometrical conditions. The conservative free surface (CLS) scheme was implemented in the original Cgles code to capture the free surface effect.
A series of simulations of turbulent flow in an open channel with different slope conditions were conducted using the modified free surface code. Supercritical flow with Froude number up to 1.94 was simulated and a decrease of the integral constant in the law of the wall has been noticed which matches well with the experimental data.
Further simulations of the marine current turbine in turbulent flow have been carried out for different operating conditions and good match with experimental data was observed for all flow conditions. The effect of waves on the performance of the turbine was also investigated and it has been noticed that this existence will increase the power performance of the turbine due to the increase of free stream velocity
Goldstone Modes and Clebsch-Gordan Coefficients
We solve explicitly the Goldstone modes in spontaneously symmetry breaking
models with supersymmetry. We find that, when more than one fields or
representations contribute to the symmetry breaking, there exist identities
among the Clebsch-Gordan coefficients which can be used as consistent checks on
the calculations.Comment: 13 page
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