  We investigate the modification of antikaons in isospin symmetric and
asymmetric nuclear matter. Using the leading s-wave couplings of the SU(3)
chiral meson-baryon Lagrangian we solve the coupled channel kaon-nucleon
scattering equation selfconsistently. The in-medium antikaon propagator is
calculated for different densities and different proton/neutron ratios. The
spectral function of the antikaon is found to be broadened strongly, and its
mass is shifted downward significantly. However, comparing the effective
in-medium mass of the antikaon to the relevant charge chemical potential of
neutron star matter, we find that kaon condensation is unlikely to occur in
neutron stars.
