Related papers: A Comment on String Solitons
On compactification to six spacetime dimensions, the fundamental heterotic string admits as a soliton a dual string whose effective worldsheet action couples to the background fields of the dual formulation of six-dimensional supergravity.…
The open N=2 string theory is defined on the four-dimensional space-time with the split signature (+,+,-,-). The string field theory action of the open N=2 string theory is described by the four-dimensional Wess-Zumino-Witten (WZW_4) model.…
We investigate infinite strings in $(2+1)D$ space-time, which may be considered as excitations of straight lines on the spatial plane. We also propose the hamiltonian description of such objects that differs from the standard hamiltonian…
After simultaneous compactification of spacetime and worldvolume on $K3$, the $D=10$ heterotic fivebrane with gauge group $SO(32)$ behaves like a $D=6$ heterotic string with gauge group $SO(28) \times SU(2)$, but with Kac--Moody levels…
The existence of maximally supersymmetric solutions to heterotic string theory that are not toroidal compactifications of the ten-dimensional superstring is established. We construct an exact fermionic realization of an N=1 supersymmetric…
We present a general algorithm which permits to construct solutions in string cosmology for heterotic and type-IIB superstrings in four dimensions. Using a chain of transformations applied in sequence: conformal, T-duality and SL(2,R)…
We compute the exact effective string vacuum backgrounds of the level $k = 81/19 SU(2,1)/U(1)$ coset model. A compact SU(2) isometry present in this seven dimensional solution allows to interpreting it after compactification as a four…
I suggest the possibility of a new string in ten dimensions. Evidence for this string is presented both from orientifold physics and from K-theory, along with a mystery concerning the M-theory description. Motivated by this possibility,…
We derive the ten-dimensional effective action of the strongly coupled heterotic string as the low energy limit of M-theory on S^1/Z_2. In contrast to a conventional dimensional reduction, it is necessary to integrate out nontrivial heavy…
Boson stars are stationary soliton-like gravitational configurations supported by a complex scalar field charged under the global $U(1)$ symmetry. We discuss properties of boson stars in type IIB supergravity approximation to string theory.…
We solve the dilaton field equation in the background of a spherically symmetric black hole in bosonic or heterotic string theory with curvature-squared corrections in arbitrary d spacetime dimensions. We then apply this result to obtain a…
We classify the spherically symmetric solutions of the Einstein-Maxwell Dilaton field equations in D dimensions and find some exact solutions of the string theory at all orders of the string tension parameter. We also show the uniqueness of…
We give a lightning introduction to critical string theory, including the 26-dimensional bosonic string, the 10-dimensional superstrings and heterotic strings with and without spacetime supersymmetry. We also discuss open strings and…
We find several classes of exact classical solutions of critical bosonic string theory, constructed as twisted products of one Euclidean and one Minkowskian 2D black hole coset. One class of these solutions leads (after tensoring with free…
This note is devoted to the study of the classical solutions on the bosonic string with euclidean world-sheet in AdS(5)xS(5). We generalize solutions presented in arXiv:0707.4254 [hep-th] to the case where we include the dynamics of the…
We explore the possibility of string theories in only four spacetime dimensions without any additional compactified dimensions. We show that, provided the theory is defined in curved spacetime that has a cosmological interpration, it is…
We suggest that the boundary cosmological constant \zeta in c<1 unitary string theory be regarded as the one-dimensional complex coordinate of the target space on which the boundaries of world-sheets can live. From this viewpoint we…
Three-dimensional string theories with 16 supersymmetries are believed to possess a non-perturbative U-duality symmetry $SO(8,24,\Zint)$. By covariantizing the heterotic one-loop amplitude under U-duality, we propose an exact expression for…
We study a family of unstable heterotic string theories in more than ten dimensions which are connected via tachyon condensation to the ten-dimensional supersymmetric vacuum of heterotic string theory with gauge group SO(32). Calculating…
Starting with the Taub--NUT solution to Einstein's equations, together with a constant dilaton, a dyonic Taub--NUT solution of low energy heterotic string theory with non--trivial dilaton, axion and $U(1)$ gauge fields is constructed by…