We study the horizon absorption of gravitational waves in coalescing,
circularized, nonspinning black hole binaries. The horizon absorbed fluxes of a
binary with a large mass ratio (q=1000) obtained by numerical perturbative
simulations are compared with an analytical, effective-one-body (EOB) resummed
expression recently proposed. The perturbative method employs an analytical,
linear in the mass ratio, effective-one-body (EOB) resummed radiation reaction,
and the Regge-Wheeler-Zerilli (RWZ) formalism for wave extraction.
Hyperboloidal (transmitting) layers are employed for the numerical solution of
the RWZ equations to accurately compute horizon fluxes up to the late plunge
phase. The horizon fluxes from perturbative simulations and the EOB-resummed
expression agree at the level of a few percent down to the late plunge. An
upgrade of the EOB model for nonspinning binaries that includes horizon
absorption of angular momentum as an additional term in the resummed radiation
reaction is then discussed. The effect of this term on the waveform phasing for
binaries with mass ratios spanning 1 to 1000 is investigated. We confirm that
for comparable and intermediate-mass-ratio binaries horizon absorbtion is
practically negligible for detection with advanced LIGO and the Einstein
Telescope (faithfulness greater than or equal to 0.997)
