122176004
New test for spontaneous breakdown of supersymmetry
We propose a new nonperturbative test for supersymmetry breaking. The test is first to break supersymmetry by introducing a lattice and then to study the behavior of the ground-state energy as a function of the lattice spacing a. We assume that as a approaches zero, E/sub 0/approx.ca/sup ..gamma../, where c is a nonzero constant and ..gamma.. is a critical exponent. If ..gamma.. is positive as a..-->..0, the ground-state energy of the continuum theory is zero and the theory is supersymmetric. On the other hand, if ..gamma.. is zero or negative, then supersymmetry is broken. We verify this test in the context of supersymmetric quantum mechanics using a strong-coupling expansion to calculate E/sub 0/ and ..gamma... We find that for the supersymmetric version of g/sup 2/x/sup 6/ quantum mechanics, ..gamma.. = 1.16 +- 0.02, whereas ..gamma.. is consistent with zero when we consider the supersymmetric extension of g/sup 2/x/sup 4/ theory.
39204644
Thermal Operator and Cutting Rules at Finite Temperature and Chemical Potential
In the context of scalar field theories, both real and complex, we derive the cutting description at finite temperature (with zero/finite chemical potential) from the cutting rules at zero temperature through the action of a simple thermal operator. We give an alternative algebraic proof of the largest time equation which brings out the underlying physics of such a relation. As an application of the cutting description, we calculate the imaginary part of the one-loop retarded self-energy at zero/finite temperature and finite chemical potential and show how this description can be used to calculate the dispersion relation as well as the full physical self-energy of thermal particles.
18810830
The sTB-B hierarchy
Abstract We construct a new supersymmetric two boson (sTB-B) hierarchy and study its properties. We derive the conserved quantities and the Hamiltonian structures (proving the Jacobi identity) for the system. We show how this system gives the sKdV-B equation and its Hamiltonian structures upon appropriate reduction. We also describe the zero curvature formulation of this hierarchy both in the superspace as well as in components.
120503298
Systematic expansion for compact QED near weak coupling
123610301
The hamiltonian structures of the KP hierarchy
Abstract We obtain the two hamiltonian structures of the KP hierarchy following the method of Drinfeld and Sokolov. We point out how the second structure of Drinfeld and Sokolov needs to be modified in the present case. We briefly comment on the connection between these structures and the W 1+∞ algebra.
119380448
DYNAMICAL SUPERSYMMETRY
We show, in a simple quantum mechanical model, how a theory can become supersymmetric in the presence of interactions even when the free theory is not. This dynamical generation of supersymmetry relaxes the condition on the equality of masses of the superpartners which would be of phenomenological interest.
16528412
Anomalous magnetic moment of electron in Chern–Simons QED
Abstract We calculate the anomalous magnetic moment of the electron in the Chern–Simons theory in 2+1 dimensions with and without a Maxwell term, both at zero temperature as well as at finite temperature. In the case of the Maxwell–Chern–Simons (MCS) theory, we find that there is an infrared divergence, both at zero as well as at finite temperature, when the tree level Chern–Simons term vanishes, which suggests that a Chern–Simons term is essential in such theories. At high temperature, the thermal correction in the MCS theory behaves as 1 β ln βM , where β denotes the inverse temperature and M , the Chern–Simons coefficient. On the other hand, we find no thermal correction to the anomalous magnetic moment in the pure Chern–Simons (CS) theory.
115132692
Hard thermal effective actions in the Schwinger formulation
We derive the properties of hard thermal effective actions in gauge theories from the point of view of Schwinger's proper time formulation. This analysis is simplified by introducing a set of generalized energy and momenta which are conserved and are nonlocal in general. These constants of motion, which embody energy-momentum exchanges between the fields and the particles along their trajectories, can be related to a class of gauge invariant or covariant potentials in the hard thermal regime. We show that in this regime the generalized energy, which is nonlocal in general, generates the characteristic nonlocal behavior of the hard thermal effective actions.
118062846
Supersymmetry in Singular Quantum Mechanics
The breaking of supersymmetry due to singular potentials in supersymmetric quantum mechanics is critically analyzed. It is shown that, when properly regularized, these potentials respect supersymmetry, even when the regularization parameter is removed.
118968179
Light-front Schwinger model at finite temperature
We study the light-front Schwinger model at finite temperature following the recent proposal in \cite{alves}. We show that the calculations are carried out efficiently by working with the full propagator for the fermion, which also avoids subtleties that arise with light-front regularizations. We demonstrate this with the calculation of the zero temperature anomaly. We show that temperature dependent corrections to the anomaly vanish, consistent with the results from the calculations in the conventional quantization. The gauge self-energy is seen to have the expected non-analytic behavior at finite temperature, but does not quite coincide with the conventional results. However, the two structures are exactly the same on-shell. We show that temperature does not modify the bound state equations and that the fermion condensate has the same behavior at finite temperature as that obtained in the conventional quantization.
16121968
Finite temperature field theories on the light front
In this talk, we describe our present understanding of thermal field theories on the light-front with an application to Schwinger model.