ترغب بنشر مسار تعليمي؟ اضغط هنا

Gauge Invariance and Effective Actions in D=3 at Finite Temperature

202   0   0.0 ( 0 )
 نشر من قبل Fosco
 تاريخ النشر 1997
  مجال البحث
والبحث باللغة English




اسأل ChatGPT حول البحث

For background gauge field configurations reducible to the form Amu = (A3, A(x)) where A3 is a constant, we provide an elementary derivation of the recently obtained result for the exact induced Chern-Simons (CS) effective action in QED3 at finite temperature. The method allows us to extend the result in several useful ways: to obtain the analogous result for the `mixed CS term in the Dorey-Mavromatos model of parity-conserving planar superconductivity, thereby justifying their argument for flux quantization in the model; to the induced CS term for a tau-dependent flux; and to the term of second order in A(x) (and all orders in A3) in the effective action.



قيم البحث

اقرأ أيضاً

We study the variations of the worldvolume fields in the non-Abelian action for multiple D-branes. Using T-duality we find that the embedding scalars transform non-trivially under NS-NS gauge transformations as delta X ~ [X, X] and prove that the non -Abelian Chern-Simons action is invariant under these transformations. Given that T-duality relates the (part of the) NS-NS transformation with (part of the) general coordinate transformations, we can get some insight in the structure of non-Abelian coordinate transformations.
93 - Sergei M. Kuzenko 2020
In both ${cal N}=1$ and ${cal N}=2$ supersymmetry, it is known that $mathsf{Sp}(2n, {mathbb R})$ is the maximal duality group of $n$ vector multiplets coupled to chiral scalar multiplets $tau (x,theta) $ that parametrise the Hermitian symmetric space $mathsf{Sp}(2n, {mathbb R})/ mathsf{U}(n)$. If the coupling to $tau$ is introduced for $n$ superconformal gauge multiplets in a supergravity background, the action is also invariant under super-Weyl transformations. Computing the path integral over the gauge prepotentials in curved superspace leads to an effective action $Gamma [tau, bar tau]$ with the following properties: (i) its logarithmically divergent part is invariant under super-Weyl and rigid $mathsf{Sp}(2n, {mathbb R})$ transformations; (ii) the super-Weyl transformations are anomalous upon renormalisation. In this paper we describe the ${cal N}=1$ and ${cal N}=2$ locally supersymmetric induced actions which determine the logarithmically divergent parts of the corresponding effective actions. In the ${cal N}=1$ case, superfield heat kernel techniques are used to compute the induced action of a single vector multiplet $(n=1)$ coupled to a chiral dilaton-axion multiplet. We also describe the general structure of ${cal N}=1$ super-Weyl anomalies that contain weight-zero chiral scalar multiplets $Phi^I$ taking values in a Kahler manifold. Explicit anomaly calculations are carried out in the $n=1$ case.
The one-loop effective potential for gauge models in static de Sitter space at finite temperatures is computed by means of the $zeta$--function method. We found a simple relation which links the effective potentials of gauge and scalar fields at all temperatures. In the de Sitter invariant and zero-temperature states the potential for the scalar electrodynamics is explicitly obtained, and its properties in these two vacua are compared. In this theory the two states are shown to behave similarly in the regimes of very large and very small radii a of the background space. For the gauge symmetry broken in the flat limit ($a to infty$) there is a critical value of a for which the symmetry is restored in both quantum states. Moreover, the phase transitions which occur at large or at small a are of the first or of the second order, respectively, regardless the vacuum considered. The analytical and numerical analysis of the critical parameters of the above theory is performed. We also established a class of models for which the kind of phase transition occurring depends on the choice of the vacuum.
579 - Sang Pyo Kim 2010
We advance a novel method for the finite-temperature effective action for nonequilibrium quantum fields and find the QED effective action in time-dependent electric fields, where charged pairs evolve out of equilibrium. The imaginary part of the effe ctive action consists of thermal loops of the Fermi-Dirac or Bose-Einstein distribution for the initial thermal ensemble weighted with factors for vacuum fluctuations. And the real part of the effective action is determined by the mean number of produced pairs, vacuum polarization, and thermal distribution. The mean number of produced pairs is equal to twice the imaginary part. We explicitly find the finite-temperature effective action in a constant electric field.
In arXiv:1403.0389 and arXiv:1610.07140 intersecting $D$-branes in flat space were studied at finite temperature in the Yang-Mills approximation. The one-loop correction to the tachyon mass was computed and the critical temperature at which the tachy on becomes massless was obtained numerically. In this paper we extend the computation of one-loop two-point amplitude to the case of intersecting stacks of $D3$-branes in flat space. The motivation for this calculation is to study the strong coupling holographic BCS model proposed in arXiv:1104.2843 at finite temperature. We show that the analytical results of arXiv:1403.0389 and arXiv:1610.07140 can be embedded into this more general setup. The main technicality involved here is keeping track of the extra color factors coming from the unbroken gauge groups. We further discuss the issues involved in the computation of two point amplitude for case of multiple intersecting stacks of branes.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا