  By comparing single-particle spectral functions of t-J and Hubbard models
with recent angle-resolved photoemission (ARPES) results for LSCO and Nd-LSCO,
we can decide where holes go as a function of doping, and more specifically,
which type of stripe (bond-, site-centered) is present in these materials at a
given doping. For dopings greater than about 12% our calculation shows
furthermore that the holes prefer to proliferate out of the metallic stripes
into the neighboring antiferromagnetic domains. The spectra were calculated by
a cluster perturbation technique, for which we present an alternative
formulation. Implications for the theory for high-Tc superconductivity are
discussed.
