Related papers: A Locally Supersymmetric Action for the Bosonic St…
The Hamiltonian analysis of Polyakov action is reviewed putting emphasis in two topics: Dirac observables and gauge conditions. In the case of the closed string it is computed the change of its action induced by the gauge transformation…
We extend some aspects of vacuum string field theory to superstring field theory in Berkovits' formulation, and we study the star algebra in the fermionic matter sector. After clarifying the structure of the interaction vertex in the…
The appearance of non(anti)commutativity in superstring theory, satisfying the Neveu-Schwarz boundary conditions is discussed in this paper. Both an open free superstring and also one moving in a background antisymmetric tensor field are…
Referring to the supermultiplet of N=1 supergravity (SUGRA) the linearization of N=1 SGM action describing the nonlinear supersymmetric (NL SUSY) gravitational interaction of superon (Nambu-Goldstone fermion) is attempted. The field…
The first class constraints in N = 1 supergravity in 2 + 1 dimensions are used to construct a generator of three gauge symmetries (including a local supersymmetry) that leave the action invariant. The algebra of these symmetries closes.…
We construct superconformal mechanics with $N=3$ and $N=4$ supersymmetries that were inspired by analogies with the supersymmetric Schwarzian mechanics. The Schwarzian, being another system with superconformal symmetry, provides insight…
We consider type IIB string interaction on the maximally supersymmetric pp-wave background and discuss how the bosonic symmetries of the background are realized. This analysis shows that there are some interesting differences with respect…
In this article we establish the relationship between fermionic T-duality and momenta noncommuativity. This is extension of known relation between bosonic T-duality and coordinate noncommutativity. The case of open string propagating in…
We provide the geometric actions for most general N=1 supergravity in two spacetime dimensions. Our construction implies an extension to arbitrary N. This provides a supersymmetrization of any generalized dilaton gravity theory or of any…
Supersymmetry plays a main role in all current thinking about superstring theory. Indeed, many remarkable properties of string theory have been explained using supersymmetry as a tool. So far, there has been no unbroken supersymmetry…
By "untwisting" the construction of Berkovits and Vafa, one can see that the N=1 superstring contains a topological twisted N=2 algebra, with central charge c^ = 2. We discuss to what extent the superstring is actually a topological theory.
A new approach to composite superconformal strings is considered . This composite string model has two scales: first one (~1 Gev) is for edging surfaces and second one (Planck scale) is for ridge surfaces . Nonlinear realization of…
The nonlinear realization of the superconformal symmetry in two dimensions is considered. The superconformal symmetry is realized by means of dimension $-1/2$\ Nambu-Goldstone fermion $\xi$\ and its dimension 3/2 conjugate $\eta$. A matter…
We construct O(D,D) invariant actions for the bosonic string and RNS superstring, using Hamiltonian methods and ideas from double field theory. In this framework the doubled coordinates of double field theory appear as coordinates on phase…
An infinite series of Grassmann-odd and Grassmann-even flow equations is defined for a class of supersymmetric integrable hierarchies associated with loop superalgebras. All these flows commute with the mutually commuting bosonic ones…
We show that almost all string theories, including the bosonic string, the superstring and $W$-string theories, possess a twisted N=2 superconformal symmetry. This enables us to establish a connection between topological gravity and the…
Supersymmetrization of a nonlinear evolution equation in which the bosonic equation is independent of the fermionic variable and the system is linear in fermionic field goes by the name B-supersymmetrization. This special type of…
We carry out the first holographic calculation of a fermionic response function for a strongly coupled $d=3$ system with an explicit D=10 or D=11 supergravity dual. By considering the supersymmetry current, we obtain a universal result…
The first part of this thesis is a general introduction to the bosonic and fermionic string theory, to the concept of D brane and to string dualities. A discussion of anomalies cancellation closes the chapter. The second part of the thesis…
We explore the geometry of the superconformal moduli of the NSR superstring theory in order to construct the consistent sigma-model for the NSR strings, free of picture-changing ambiguities. The sigma-model generating functional is…