Recent achievements in the theoretical description of exciton transfer in photosynthetic antennae are reviewed.
Emphasis is put on the role of the protein matrix in the process of excitation energy dissipation.
The computations are based on the standard Frenkel-exciton model including some necessary extensions. To carry out the simulations of experimental spectra the density-matrix theory is utilized. A numerical Monte Carlo treatment is applied to account for structural and energetic disorder. The approach is used to interpret various measurements on photosynthetic antenna systems. In particular, it is demonstrated how the exciton spectrum can be used as a probe for the protein spectral density.