A cosmologist's excursion into geophysics

A Short Excursion into Semi-Algebraic Hierarchies

This brief survey gives a (roughly) self-contained overview of some complexity theoretic results about semi-algebraic proof systems and related hierarchies and the strong connections between them. The article is not intended to be a detailed survey on “Lift and Project” type optimization hierarchies (cf. Chlamtac and Tulsiani [12]) or related proof systems (cf. Grigoriev et al. [16]).

An excursion into geometric analysis

An excursion into pharmacology: curare in medicine.

INTRODUCTION IN our present age of specialization, it is not easy to move from one branch of medical study to another in pursuit of a single piece of research, a single enquiry. Fifty years ago, Sir Thomas Lewis wrote that on occasion it may be desirable for the clinical scientist to become his own pharmacologist. And fifty years ago, the present writer, a clinician, made an excursion into phar...

“An Excursion into Set Theory using a Constructivist Approach”

Constructive logic is an alternative to the theory of classical logic that draws a direct relation between an assertion and its existence. Some of the few important differences between a classical proof and a constructionist proof include the avoidance of proof by contradiction and the rejection of the law of the excluded middle. However, given the possibility that constructive logic is an alte...

Cosmological neutrino bounds for non-cosmologists

I briefly review cosmological bounds on neutrino masses and the underlying gravitational physics at a level appropriate for readers outside the field of cosmology. For the case of three massive neutrinos with standard model freezeout, the current 95% upper limit on the sum of their masses is 0.42 eV. I summarize the basic physical mechanism making matter clustering such a sensitive probe of mas...