# Is there a background independent closed string field theory?

+ 8 like - 0 dislike
718 views

Analogous to the background independent open string field theory by Witten. If there isn't, what are the main stumbling blocks preventing its construction?

This post has been migrated from (A51.SE)

+ 8 like - 0 dislike

An original article is

• Ashoke Sen, Barton Zwiebach, Quantum Background Independence of Closed String Field Theory (arXiv:hep-th/9311009)

An old spr comment by Sabbir Rahman gives a survey of the history of some of these developments.

More references are here.

This post has been migrated from (A51.SE)
answered Oct 21, 2011 by (5,455 points)
As far as I understand, Sen and Zweibach consider "usual" closed string theory, which is not manifestly background independent, and prove that the theories on different backgrounds are equivalent. However, Witten's theory uses the space of backgrounds (BCFTs) as a classical history space which is a manifestly background independent framework. The problem is that he considers BCFTs with different boundary behavior but the same worldsheet-bulk behavior. Apparently this is sufficient for the same reason ordinary open string field theory contains closed strings.

This post has been migrated from (A51.SE)
However, one would like to have a closed string analogue, that is, a theory whose classical history space is the space of all CFTs. This would be framework with completely manifest background independence.

This post has been migrated from (A51.SE)
Sure, but you asked "is there background independent CSFT?". The closest to *manifest* background invariance in CSFT that I am aware of is Sen, Zwiebach "Background Independent Algebraic Structures in Closed String Field Theory" ([arXiv:hep-th/9408053](http://arxiv.org/abs/hep-th/9408053))

This post has been migrated from (A51.SE)

 Please use answers only to (at least partly) answer questions. To comment, discuss, or ask for clarification, leave a comment instead. To mask links under text, please type your text, highlight it, and click the "link" button. You can then enter your link URL. Please consult the FAQ for as to how to format your post. This is the answer box; if you want to write a comment instead, please use the 'add comment' button. Live preview (may slow down editor)   Preview Your name to display (optional): Email me at this address if my answer is selected or commented on: Privacy: Your email address will only be used for sending these notifications. Anti-spam verification: If you are a human please identify the position of the character covered by the symbol $\varnothing$ in the following word:p$\hbar$ysicsOv$\varnothing$rflowThen drag the red bullet below over the corresponding character of our banner. When you drop it there, the bullet changes to green (on slow internet connections after a few seconds). To avoid this verification in future, please log in or register.