On Aspects and Implications of the New Covariant 4D, N = 1 Green-Schwarz Sigma-model Action

Utilizing (2,0) superfields, we write a supersymmetry-squared action and partially relate it to the new formulation of the Green-Schwarz action given by Berkovits and Siegel. Recent results derived from this new formulation are discussed within the context of some prior proposals in the literature. Among these, we note that 4D, N = 1 beta-FFC superspace geometry with a composite connection for R-symmetry has now been confirmed as the only presently known limit of 4D, N = 1 heterotic string theory that is derivable in a completely rigorous manner.Comment: 15 pages, LaTe

Quantization of N=1 chiral/nonminimal (CNM) scalar multiplets and supersymmetric Yang-Mills theories

We give the superfield quantization of chiral/nonminimal (CNM) scalar multiplets defined by pairs of N=1 chiral and complex linear scalar superfields kinematically coupled. In the pure massive case we develop the covariant quantization when CNM multiplets are coupled to background gauge superfields. Furthermore, we study some properties of N=1 supersymmetric Yang--Mills theories constructed using CNM scalar matter superfields. In particular, we compute the one--loop contribution to the effective action for the matter superfields, we study the analogue of the Konishi anomaly and discuss some properties of the glueball superpotential.Comment: 15 pages, LaTeX, references added, new comments in section 2, section 4 modified, new section 6 inserted, version to appear on Phys. Lett.

Two Two-Dimensional Supergravity Theories from Calabi-Yau Four-Folds

We consider two-dimensional supergravity theories with four supercharges constructed from compactification of Type II string theory on a generic Calabi-Yau four-fold. In Type IIA and Type IIB cases, respectively, new superspace formulations of N=(2,2) and N=(0,4) dilaton supergravities are found and their coupling to matter multiplets is discussed.Comment: 47 pages, harvma

Consistency of Superspace Low Energy Equations of Motion of 4D Type II Superstring with Type II Sigma Model at Tree-Level

We derive the torsion constraints and show the consistency of equations of motion of four-dimensional Type II supergravity in superspace, with Type II sigma model. This is achieved by coupling the four-dimensional compactified Type II Berkovits' superstring to an N=2 curved background and requiring that the sigma-model has superconformal invariance at tree-level. We compute this in a manifestly 4D N=2 supersymmetric way. The constraints break the target conformal and SU(2) invariances and the dilaton will be a conformal, $SU(2)\times U(1)$ compensator. For Type II superstring in four dimensions, worldsheet supersymmetry requires two different compensators. One type is described by chiral and anti-chiral superfields. This compensator can be identified with a vector multiplet. The other Type II compensator is described by twist-chiral and twist-anti-chiral superfields and can be identified with a tensor hypermultiplet. Also, the superconformal invariance at tree-level selects a particular gauge, where the matter is fixed, but not the compensators. After imposing the reality conditions, we show that the Type II sigma model at tree-level is consistent with the equations of motion for Type II supergravity in the string gauge.Comment: 8 pages, changes in the title and abstract, references added, accepted for publication in Physics Letters

Chaotic inflation in F(R) supergravity

The bosonic f(R) gravity function is derived from a chiral F(R) supergravity model for the first time. We find an existence of the upper limit (or AdS bound) on the scalar curvature, as well as a solution with a vanishing cosmological constant. We compare our simple model of F(R) supergravity to the well known Starobinsky model of chaotic inflation.Comment: 11 pages, LaTeX2e, no figures; secs. 4 and 5 expanded, references adde

A New Sigma Model Action for the Four-Dimensional Green-Schwarz Heterotic Superstring

The sigma model action described in this paper differs in four important features from the usual sigma model action for the four-dimensional Green-Schwarz heterotic superstring in a massless background. Firstly, the action is constructed on an N=(2,0) super-worldsheet using a Kahler potential and an Ogievetsky-Sokatchev constraint; secondly, the target-space background fields are unconstrained; thirdly, the target-space dilaton couples to the two-dimensional curvature; and fourthly, the action reduces in a flat background to a free-field action. A conjecture is made for generalizing this N=(2,0) sigma model action to the ten-dimensional Green-Schwarz heterotic superstring in a manner that preserves these four new features.Comment: 9 pages plain Tex, KCL-TH-93-

Will the Real 4D, N=1 SG Limit of Superstring/M-Theory Please Stand Up?

At the component-level we study the `beta-function-favored constraint' (bffc) formalism, suggested in 1988 as the most natural formulation for supergravity derived from more fundamental theories. We begin with the suggestion that \bffc supergravity be identified with new minimal supergravity together with an additional chiral compensator multiplet. After $U_{\rm A}(1)$symmetry breaking, the non-propagating axion 2-form of new minimal supergravity becomes the propagating axion 2-form required by string theory. The final form of the theory is seen to uniquely allow four simultaneous features: (i) local supersymmetry, (ii) implementation of the Green-Schwarz mechanism, (iii) a supersymmetry-breaking order parameter chiral superfield, and (iv) a dilaton superpotential.Comment: Minor changes with notational improvements in eqs.(3.6), (3.9) and (3.10), a note added with ref.[22]. 12 pages, late

On Integrating Out Heavy Fields in SUSY Theories

We examine the procedure for integrating out heavy fields in supersymmetric (both global and local) theories. We find that the usual conditions need to be modified in general and we discuss the restrictions under which they are valid. These issues are relevant for recent work in string compactification with fluxes.Comment: Typos corrected, minor changes. 10 page

The N=2 Super Yang-Mills Low-Energy Effective Action at Two Loops

We have carried out a two loop computation of the low-energy effective action for the four-dimensional N=2 supersymmetric Yang-Mills system coupled to hypermultiplets, with the chiral superfields of the vector multiplet lying in an abelian subalgebra. We have found a complete cancellation at the level of the integrands of Feynman amplitudes, and therefore the two loop contribution to the action, effective or Wilson, is identically zero.Comment: 8 pages, Latex, 2 .eps figure

``Alternative N=(4,0)N=(4,0) Superstring and \s-Models''

We present an alternative $N=(4,0)$ superstring theory, with field content different from that of previously-known $N=(4,0)$ superstring theories. This theory is presented as a non-linear \s-model on the coset $SU(n,1) / SU(n) \otimes U(1)$ as the target space-time with torsion, which is coupled to $N=(4,0)$ world-sheet superconformal gravity. Our result indicates that the target space-time for $N=4$ superstring theory does not necessarily have to be a hyper-K\"ahler or quaternionic K\"ahler manifold.Comment: 13 pages, latex, no figure