what is it?
(i know that the one of experts in this field is Barton Zwiebach from mit).
well, im not sure either. But I'll take a shot.
Tachyon- faster than light particle
vacuum- a region with no forces to act upon an object.
It may be some type of device for detecting tachyons. Your best bet would be putting "tachyon vacuum" in a google search.
Good try, Paden, but this is not correct. The tachyon vacuum is the background scenario where is formulated Vacuum String field theory. VSFT is a reformulation of open string field theory
does the idea have similiraties to the idea of ether (besides that both of them are proposed background)?
and what was the background in OSFT?
don't know the answer to your questions, but you have to know that vacuum string field theory was introduced in this paper:
"String field theory around the tachyon vacuum"
Abstract:"Assuming that around the tachyon vacuum the kinetic term of cubic open string field theory is made purely of ghost operators we are led to gauge invariant actions which manifestly implement the absence of open string dynamics around this vacuum. We test this proposal by showing the existence of lump solutions of arbitrary codimension in this string field theory. The key ingredients in this analysis are certain assumptions about the analyticity properties of tachyon Green's functions. With the help of some further assumptions about the properties of these Green's functions, we also calculate the ratios of tensions of lump solutions of different dimensions. The result is in perfect agreement with the known answers for the ratios of tensions of D-branes of different dimensions."
Perhaps you can find there the answers
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