Finite temperature spectral function of Mott insulators and charge density wave states

We calculate the low-temperature spectral function of one-dimensional incommensurate charge density wave states and half filled Mott insulators. At T=0 there are two dispersing features associated with the spin and charge degrees of freedom, respectively. We show that already at very low temperatures (compared to the gap) one of these features gets severely damped. We comment on implications of this result for photoemission experiments.     

A ``nonlinear' proof of Pitt's compactness theorem

Using Stegall's variational principle, we present a simple proof of Pitt's theorem that bounded linear operators from into are compact for .

     

The range of the gradient of a LipschitzC 1-smooth bump in infinite dimensions

If a Banach space has a LipschitzC ¹-smooth bump function, then it admits other bumps of the same smoothness whose gradients exactly fill the dual unit ball and other reasonable figures. This strengthens a result of Azagra and Deville who were able to cover the dual unit ball. Supported in part by NSERC and the Canada Research Chair Programme. Supported in part by grants NATO CRG-973982, GAĈR 201-01-1198, and AV 1019003 (Czech Republic). Supported in part by NATO CRG-973982 and NSERC.     

The Radical Anions of Some Benzo-Derivatives of Dehydrocyclooctatetraenes

The radical anions of 5,6-didehydrobenzocyclooctene ( 3 ), 5,6,9,10-tetradehydrobenzocyclooctene ( 4 ) and 1,4,7,10-tetramethyl-5,6-didehydrodibenzo[a, e]-cyclooctene ( 6 ) were prepared in situ from dibromo-precursors and have been characterized by ESR and ENDOR spectroscopy.     

Soft X-ray band emission from solids

Interest in soft x-ray spectroscopy of solids has seen a sharp revival in the past ten years, and the many advances during that time have been both experimental and theoretical. Following the initial impetus given to the subject in the period from about 1936 to the late 1940's, chiefly by the experimental work of Farineau,¹ Skinner,² and Cauchois,³ coupled with the theoretical groundwork of Mott and Jones,⁴ the field remained almost static for nearly a decade. Then two largely complementary review articles, by D. H. Tomboulian⁵ in 1957 and L. G. Parratt⁶ in 1959, respectively, probably brought the renewal of interest observed in the 1960's and certainly formed a springboard for the steady development of experimental and theoretical techniques that has since occurred. Most of the material in those two surveys remains today as an important framework around which the subject has grown.