53,407 research outputs found
Thermodynamic potentials and Thermodynamic Relations in Nonextensive Thermodynamics
The generalized Gibbs free energy and enthalpy is derived in the framework of
nonextensive thermodynamics by using the so-called physical temperature and the
physical pressure. Some thermodynamical relations are studied by considering
the difference between the physical temperature and the inverse of Lagrange
multiplier. The thermodynamical relation between the heat capacities at a
constant volume and at a constant pressure is obtained using the generalized
thermodynamical potential, which is found to be different from the traditional
one in Gibbs thermodynamics. But, the expressions for the heat capacities using
the generalized thermodynamical potentials are unchanged.Comment: 7 page
Heat capacity of the generalized two-atom and many-atom gas in nonextensive statistics
We have used the generalized two-atom ideal gas model in Tsallis statistics
for the statistical description of a real gas. By comparing the heat capacity
with the experimental results for the two-atom molecule gases such as N2, O2
and CO, we find that these gases appear extensive at normal temperature, but
they may be nonextensive at the lower temperature. Furthermore, we study the
heat capacity of the generalized many-atom gas model. We conclude that, for the
many-atom gas with a high degree of freedom, a weak nonextensivity of 1-q<0 can
lead to the instability.Comment: 12 pages, 2 figures, 1 table, 32 reference
Heat-kernel approach for scattering
An approach for solving scattering problems, based on two quantum field
theory methods, the heat kernel method and the scattering spectral method, is
constructed. This approach converts a method of calculating heat kernels into a
method of solving scattering problems. This allows us to establish a method of
scattering problems from a method of heat kernels. As an application, we
construct an approach for solving scattering problems based on the covariant
perturbation theory of heat-kernel expansions. In order to apply the
heat-kernel method to scattering problems, we first calculate the off-diagonal
heat-kernel expansion in the frame of the covariant perturbation theory.
Moreover, as an alternative application of the relation between heat kernels
and partial-wave phase shifts presented in this paper, we give an example of
how to calculate a global heat kernel from a known scattering phase shift
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