In the context of brane world scenario, cosmic superstrings can be formed in D-brane annihilation at the end of the brane inflationary era. This cosmic superstring network has a scaling solution and the characteristic scale of the network is proportional to the square root of the reconnection probability. PACS numbers: 11.25.-w, 11.25.Uv, 11.27.+d A Note on the evolution of cosmic string/supers...

In this short note we would like to discuss general solutions of the Berkovits superstring field theory, in particular the string field action for fluctuation around such a solution. We will find that fluctuations obey the same equation of motion as the original field with the new BRST operator. Then we will argue that the superstring field theory action for fluctuation field has the same form ...

It appears that the formulation of an action for the Ramond sector of open superstring field theory requires to either restrict the Hilbert space for the Ramond sector or to introduce auxiliary fields with picture −3/2. The purpose of this note is to clarify the relation of the restricted Hilbert space with other approaches and to formulate open superstring field theory entirely in the small Hi...

We show that the tree-level S-matrices of superstring field theories based on homotopy-algebra structure agree with those obtained in first-quantized formulation. The proof is given detail for heterotic string theory. extensions to type II and open are straightforward.

Although the equations of motion for the Neveu-Schwarz (NS) and Ramond (R) sectors of open superstring field theory can be covariantly expressed in terms of one NS and one R string field, picture-changing problems prevent the construction of an action involving these two string fields. However, a consistent action can be constructed by dividing the NS and R states into three string fields which...

We consider the problem of finding quasiperiodicities in a Fibonacci string. A factor u of a string y is a cover of y if every letter of y falls within some occurrence of u in y. A string v is a seed of y, if it is a cover of a superstring of y. A left seed of a string y is a prefix of y that it is a cover of a superstring of y. Similarly a right seed of a string y is a suffix of y that it is a...

We investigate the correspondence between superstring theory on pp-wave background with NSNS-flux and superconformal field theory on a symmetric orbifold. This correspondence can be regarded as the “Penrose limit” of AdS3/CFT2 correspondence. Superstring theory on the Penrose limit of AdS3 ×S3(×M4) (M4 = T 4 orK3) with NSNS-flux can be described by a generalization of Nappi-Witten model. We qua...

The best known approximation ratio for the shortest superstring problem is 2 11 23 (Mucha, 2012). In this note, we improve this bound for the case when the length of all input strings is equal to r, for r ≤ 7. For example, for strings of length 3 we get a 1 1 3 -approximation. An advantage of the algorithm is that it is extremely simple both to implement and to analyze. Another advantage is tha...

Superstrings have many applications in data compression and genetics. However the decision version of the shortest superstring problem is NP-complete. In this paper we examine the complexity of approximating a shortest superstring. There are two basic measures of the approximations: the compression ratio and the approximation ratio. The well known and practical approximation algorithm is the se...

We focus on the combinatorial analysis of physical mapping with repeated probes. We present computational complexity results, and we describe and analyze an algorithmic strategy. We are following the research avenue proposed by Karp [9] on modeling the problem as a combinatorial problem – the Hypergraph Superstring Problem – intimately related to the Lander-Waterman stochastic model [16]. We sh...