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In their Letter "Excitons in Molecular Aggregates with Levy Disorder: Anomalous Localization and Exchange Broadening of Optical Spectra", Eisfeld et al. predicted the existence of exchange broadening and blue-shift of the absorption band and a non-universal disorder scaling of the localisation length of absorption band excitons in J-aggregates with heavy-tailed disorder, which they contrasted with the previously analysed Gaussian and Lorentzian case. The observations were explained by another localisation mechanism, the chain segmentation by outliers in heavy tails of the disorder distribution. We argue that the previously known theory does not break down and consequently anticipates the properties of the absorption band investigated in the commented work., 9 pages, 8 figures

The Comment to the Letter "Excitons in Molecular Aggregates with Levy Disorder: Anomalous Localization and Exchange Broadening of Optical Spectra" appeared in Phys. Rev. Lett. 109, 259701 (submitted on November 28, 2011). I prepared the below response to the rebuttal received from the Letter's Authors in the review process. It contains useful comments, which further address the errors in the Letter and other flaws in Authors' understanding of the topic revealed in discussion., Comment: 9 pages, 7 figures

This appendix to the paper by Werpachowska and Dietl "Theory of spin waves in ferromagnetic (Ga,Mn)As" (DOI: 10.1103/PhysRevB.82.085204) is a response to inquiries about the derivation of the Loewdin calculus and its numerical implementation. It presents the detailed version of the Loewdin calculus for the multiband Hamiltonian taking into account both the p-d and s-d exchange couplings. This should explain how to implement the sp-d exchange interaction in the tight-binding computational scheme. I also include the complete procedure of the Bogoliubov transform for systems with spatial inversion asymmetry., Comment: 8 + epsilon pages, no figures, one column (corrected)