28 research outputs found
Second Order Corrections to QED Coupling at Low Temperature
We calculate the second order corrections to vacuum polarization tensor of
photons at low temperatures, i.e; T K (). The thermal
contributions to the QED coupling constant are evaluated at temperatures below
the electron mass that is . Renormalization of QED at these
temperatures has explicitly been checked. The electromagnetic properties of
such a thermal medium are modified. Parameters like electric permittivity and
magnetic permeability of such a medium are no more constant and become
functions of temperature.Comment: 8 latex pages and 1 figure (to appear in IJMP
Second Order Corrections to the Magnetic Moment of Electron at Finite Temperature
Magnetic moment of electron at finite temperature is directly related to the
modified electron mass in the background heat bath. Magnetic moment of electron
gets modified when it couples with the magnetic field at finite temperature
through its temperature dependent physical mass. We show that the magnetic
moment of electron becomes a complicated function of temperature and even
change its temperature dependent behavior around the energies for primordial
nucleosynthesis. We calculate the self-mass induced thermal contributions to
the magnetic moment of electron, up to the two loop level, for temperatures
valid around the era of primordial nucleosynthesis. A comparison of thermal
behavior of the magnetic moment is also quantitatively studied in detail,
around the temperatures below and above nucleosynthesis temperature range
Second Order Thermal Corrections to Electron Wavefunction
Second order perturbative corrections to electron wavefunction are calculated
here at generalized temperature, for the first time. This calculation is
important to prove the renormalizeability of QED through order by order
cancellation of singularities at higher order. This renormalized wavefunction
could be used to calculate the particle processes in the extremely hot systems
such as the very early universe and the stellar cores. We have to re-write the
second order thermal correction to electron mass in a convenient way to be able
to calculate the wavefunction renormalization constant. A procedure for
integrations of hot loop momenta before the cold loop momenta integration is
maintained throughout to be able to remove hot singularities in an appropriate
way. Our results, not only includes the intermediate temperatures T m (where m
is the electron mass), the limits of high temperature T>>m and low temperature
T<<m are also retrievable. A comparison is also done with the existing results.Comment: 12 Pages and 1 figure; Submitted for publicatio