# Michael Cohen

- Prof. Emeritus
- Postdoctoral positions al CalTech and the Institute for Advanced Study (Princeton)

Honors include:

Honorary Trustee (co-founder), Aspen Center for Physics

Fellow, American Physical Society

Ph.D., CalTech (1956)

B.A. Cornell (1951)

Condensed Matter Physics

I have investigated the quantum mechanics of liquid helium, calculating properties of the bulk fluid as well as the surface (density profile and surface excitations).

I am interested in applying statistical mechanics to the analysis of simple models of real-world systems. An analysis of a simple model of displacive ferroelectrics led to an interesting phase diagram and an understanding of mode softening as the precursor of a displacive transition. With a biologically-oriented coworker, I have studied the equilibrium between a membrane (wilh sites which can adsorb molecules) and a fluid containing those molecules. We have studied fairly complicated membranes, taking account of the geometrical competition for sites and also including electrostalic effecls in a mean-field approximation.

In September 2011 I completed an elementary text, or supplementary text, on Classical Mechanics. The book incorporates my ideas on how to present the basic concepts, and is available (free) online. (See link above).

- (with T.J. Einstein), "Statistical Mechanics of a Simple Model of a Displacive Ferroelectric," Phys. Rev. B, 7, 1932 (1973).
- (with C.C. Chang), "Microscopic Theory of Surface Excitations in Superfluid Helium," Phys. Rev. B 11, 1059 (1975).
- (with J.A. Cohen), "Adsorption of Monovalent and Divalent Cations by Phospholipid Membranes: the Monomer-Dimer Problem," Biophys. Journal 36, 623 (1981).
- (with A.B. Harris), "Scaling of Negative Moments of the Growth Probability of Diffusion Limited Aggregates" , Phys. Rev. A41, 971 (1990)
- (with A.B.Harris), "Multiple Species of Noninteracting Molecules Adsorbed on a Bethe Lattice", Phys.Rev.E78, 041116 (2008)
- "Classical Mechanics: a Critical Introduction" online 2011 (see link above)