Screened Perturbation Theory
نویسنده
چکیده
A new perturbative scheme is proposed for the evaluation of the free energy density of field theories at finite temperature. The screened loop expansion takes into account exactly the phenomenon of screening in thermal propagators. The approach is tested in the N -component scalar field theory at 2-loop level and also at 3-loop in the large N limit. The perturbative series generated by the screened loop expansion shows much better numerical convergence than previous expansions generated in powers of the quartic coupling. PACS: 11.10.Wx, 12.38.Mh
منابع مشابه
Screened perturbation theory at four loops
We study the thermodynamics of massless φ-theory using screened perturbation theory, which is a way to systematically reorganise the perturbative series. The free energy and pressure are calculated through four loops in a double expansion in powers of g and m/T , where m is a thermal mass of order gT . The result is truncated at order g. We find that the convergence properties are significantly...
متن کاملMass Expansions of Screened Perturbation Theory
The thermodynamics of massless φ4-theory is studied within screened perturbation theory (SPT). In this method the perturbative expansion is reorganized by adding and subtracting a mass term in the Lagrangian. We analytically calculate the pressure and entropy to three-loop order and the screening mass to two-loop order, expanding in powers of m/T . The truncated m/T -expansion results are compa...
متن کاملCharge screening and confinement in the massive Schwinger model
Within the framework of Euclidean path integral and mass perturbation theory we compute the Wilson loop of widely separated external charges for the massive Schwinger model. From this result we show for arbitrary order mass perturbation theory that integer external charges are completely screened, whereas for noninteger charges a constant long-range force remains.
متن کاملar X iv : h ep - p h / 00 08 02 7 v 1 3 A ug 2 00 0 Three Loop Free Energy Using Screened Perturbation Theory
The conventional weak-coupling expansion for the pressure of a hot plasma shows no sign of convergence unless the the coupling constant g is tiny. In this talk, I discuss screened perturbation theory (SPT) which is a reorganization of the perturbative expansion by adding and subtracting a local mass term in the Lagrangian. We consider several different mass prescriptions, and compute the pressu...
متن کاملScreened Perturbation Theory to Three Loops
The thermal physics of a massless scalar field with a φ interaction is studied within screened perturbation theory (SPT). In this method the perturbative expansion is reorganized by adding and subtracting a mass term in the lagrangian. We consider several different mass prescriptions that generalize the one-loop gap equation to two-loop order. We calculate the pressure and entropy to three-loop...
متن کامل