A K Rajagopal
Articles written in Proceedings – Section A
Volume 48 Issue 3 September 1958 pp 145-151
Volume 50 Issue 2 August 1959 pp 143-148
Volume 71 Issue 4 April 1970 pp 149-166
Double dispersion relations in quantum Statistical Mechanics—II
Double dispersion relations are given for the functions$$\gamma (12;3) = \frac{1}{i}\langle T\left( {\psi (1)\psi ^\dag (2)B (3)} \right)\rangle$$ common in many electron problems. Here ψ and ψ^{T} refer to electron destruction and creation operators, and B (3) is a boson or boson-like operator such as particle density, ion displacement, local spin, particle current density, or electron spin density. Consequences of Hermiticity properties and time reversal invariance as well as sum rules are established for the spectral density functions entering the double dispersion relations. A subtracted double dispersion relation is suggested for the corresponding vertex function. Details of the derivation and examples are given which were not included in an earlier brief report of this work.
Volume 78 Issue 1 July 1973 pp 13-24
Three problems and their relevance?
Three problems are posed and their solutions (ranging from complete to partial) described. They are (i) the Hydrogen atom in an intense magnetic field; (ii) the thermodynamics of one-dimensional chain of continuous spins in an external magnetic field interacting
© 2021-2022 Indian Academy of Sciences, Bengaluru.