Covariant Closed String Field Theory
Covariant closed string field theories are considerably more complicated than their open string cousins. Even if one wants to construct a string field theory which only reproduces tree-level interactions between closed strings, the classical action must contain an infinite number of vertices consisting of string polyhedra.
If one demands that on-shell scattering diagrams be reproduced to all orders in the string coupling, one must also include additional vertices arising from higher genus (and hence higher order in ) as well. In general, a manifestly BV invariant, quantizable action takes the form
where denotes an th order vertex arising from a genus surface and is the closed string coupling. The structure of the vertices is in principle determined by a minimal area prescription, although, even for the polyhedral vertices, explicit computations have only been performed to quintic order.
Read more about this topic: String Field Theory
Famous quotes containing the words closed, string, field and/or theory:
“What I call middle-class society is any society that becomes rigidified in predetermined forms, forbidding all evolution, all gains, all progress, all discovery. I call middle-class a closed society in which life has no taste, in which the air is tainted, in which ideas and men are corrupt. And I think that a man who takes a stand against this death is in a sense a revolutionary.”
—Frantz Fanon (1925–1961)
“A culture may be conceived as a network of beliefs and purposes in which any string in the net pulls and is pulled by the others, thus perpetually changing the configuration of the whole. If the cultural element called morals takes on a new shape, we must ask what other strings have pulled it out of line. It cannot be one solitary string, nor even the strings nearby, for the network is three-dimensional at least.”
—Jacques Barzun (b. 1907)
“Never in the field of human conflict was so much owed by so many to so few.”
—Winston Churchill (1874–1965)
“There could be no fairer destiny for any physical theory than that it should point the way to a more comprehensive theory in which it lives on as a limiting case.”
—Albert Einstein (1879–1955)