1. Dynamical charge susceptibility in superconducting cuprates. Mikhail Eremin Kazan State University, Russian Federation. The density-density response function is closely related to the optical conductivity in ab plane and therefore can be tested experimentally. Most interestingly a feedback of a superconductivity has been observed by the means of the optical conductivity in hole-doped [Basov et al. ] at energy 1000cm-1 (Tc = 93 K) and in the electron-doped at 100cm-1 [Pimenov et al.] (Tc = 25 K ).

2. D. N.Basov, T. Timusk et al.

4. [3] M. Eremin, I. Eremin, S. Varlamov, Phys. Rev. B 64, 214512 (2001). [4] M. Eremin, I. Eremin, A. Aleev, Physica B, (2006),

5. M. R. Norman, Phys. Rev. B 63,092509 (2001),,

6. A. Aleev,I.Eremin,M.Eremin (2006)

8. D. Manske, I. Eremin, and K. Benemann, Phys. Rev. B 62, 13922 (2000).

15. ,,