From chemistry-request@server.ccl.net Tue Aug 24 12:04:16 1999 Received: from rock.helsinki.fi (rock.helsinki.fi [128.214.3.50]) by server.ccl.net (8.8.7/8.8.7) with ESMTP id MAA23530 for ; Tue, 24 Aug 1999 12:04:15 -0400 Received: from localhost (sundius@localhost) by rock.helsinki.fi (8.8.8/8.8.5) with ESMTP id SAA18935; Tue, 24 Aug 1999 18:58:39 +0300 (EET DST) Date: Tue, 24 Aug 1999 18:58:38 +0300 (EET DST) From: Tom Sundius X-Sender: sundius@rock.helsinki.fi To: sergiusz kwasniewski cc: chemistry@ccl.net Subject: Re: CCL:RPA and second quantization In-Reply-To: <199908241119.NAA08003@alpha.luc.ac.be> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII On Tue, 24 Aug 1999, sergiusz kwasniewski wrote: > Hi CCL'ers, > > I'm currently studying polarization propagator techniques like RPA and MBGF. > Does anyone know to what the following names are related to: > Random Phase and Second Quantization. I know more or less what it is about, > but I don't seem to find the connection between the theory and the name it > is given to. > These concepts have originated in physics. Second quantization deals with the algebra of creation and annihilation operators and connects quantum field theory with many-body theories. A simple introduction to second quantization is given in Szabo and Ostlund: Modern Quantum Chemistry (Dover 1996). More can be found out from books on quantum mechanics (for instance, Baym's Lectures on quantum mechanics). The random phase approximation (RPA) is, what I can see, not treated in Szabo's and Ostlund's book, although it gives a good introduction to Green's functions. RPA is an approximation to the two-body Green's function, and was first used by in a paper by Bohm and Pines (Phys. Rev. 92, 609 (1953)) to describe plasma oscillations by assuming random phases. RPA is decribed in books on many-body theories, for instance G.E. Brown: Many-body problems, North-Holland, 1972 (probably there are some books on quantum chemistry that have it, too). Greetings, TS Tom Sundius University of Helsinki, Department of Physics phone +358-9-191 8339 P.O.Box 9, FIN-00014 Helsinki, Finland fax +358-9-191 8680