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Résumé |
I will revisit the problem of D0-brane recoil in closed string emission. At
leading order the process is perfectly well defined, but the first correction
already develops an infrared divergence in the worldsheet description. This has
long been interpreted as a signal of recoil, but there is still no formulation of
the process in terms of dynamical D0-brane states.
I will argue that the real issue is not the divergence itself, but the fact that
the worldsheet formalism treats the D0-brane as a fixed background and does not
provide a Hilbert space of states with definite momentum. As a result, momentum
conservation and recoil are not properly implemented.
I will then show that open string field theory provides the natural framework in
which the D0-brane becomes a genuine quantum object. In this setting the amplitude
is well defined, momentum conservation is manifest, and the divergence disappears. |
