Tachyon vacuum of bosonic open string field theory in marginally deformed backgrounds

Abstract:We use the recently constructed solution for marginal deformations by one of the authors, to analytically relate the BCFT modulus (λ BCFT ) to the coefficient of the boundary marginal field in the solution (λ SFT ). We explicitly find that the relation is not one to one and the same value of λ SFT corresponds to a pair of different λ BCFT 's: a "small" one, and a "large" one. The BCFT moduli space is fully covered, but the coefficient of the marginal field in the solution is not a good global coordinate on such a space.

Section: Review Of the Simple Marginal Solutionmentioning

confidence: 99%

Section: Review Of the Simple Marginal Solutionmentioning

confidence: 99%

Large BCFT moduli in open string field theory

Maccaferri

Schnabl

2015

“…Concrete examples of these 'far' solutions in OSFT have been presented in [10] and in [5] building on [11][12][13][14][15]. It is therefore an important question whether we can find these solutions in Siegel gauge as well.…”

Section: Introductionmentioning

confidence: 99%

BCFT moduli space in level truncation

Kudrna

Maccaferri

2016

We propose a new non-perturbative method to search for marginal deformations in level truncated open string field theory. Instead of studying the flatness of the effective potential for the marginal field (which is not expected to give a one-to-one parametrization of the BCFT moduli space), we identify a new non-universal branch of the tachyon potential which, from known analytic examples, is expected to parametrize the marginal flow in a much larger region of the BCFT moduli space. By a level 18 computation in Siegel gauge we find an increasingly flat effective potential in the non-universal sector, connected to the perturbative vacuum and we confirm that the coefficient of the marginal field (λ SFT ) has a maximum compatible with the value where the solutions stop existing in the standard Sen-Zwiebach approach. At the maximal reachable level the effective potential still deviates from flatness for large values of the tachyon, but the Ellwood invariants stay close to the correct BCFT values on the whole branch and the full periodic moduli space of the cosine deformation is covered.

“…This lack of linearity makes it difficult to see whether there exists a complete renormalization scheme consistent with the assumption (4b) using the approach in [1]. , equation (9). The difference is the gray strips, which are not covered using the latter choice.…”

Section: Setupmentioning

confidence: 99%

“…Earliest attempts to construct SFT solutions dealt mainly with finite boundary operators (for example, [2,3]), but the challenge due to singular operators has been mostly overcome: for marginal operators, in [1,4], and, for bcc operators, in several recent works, including [5,6,7]. Other approaches have also been considered in [8] and [9,10,11].…”

Section: Introductionmentioning

confidence: 99%

Renormalization schemes for SFT solutions

Karczmarek

Longton

2015

In this paper, we examine the space of renormalization schemes compatible with the Kiermaier and Okawa [1] framework for constructing Open String Field Theory solutions based on marginal operators with singular self-OPEs. We show that, due to freedom in defining the renormalization scheme which tames these singular OPEs, the solutions obtained from the KO framework are not necessarily unique. We identify a multidimensional space of SFT solutions corresponding to a single given marginal operator.