Notes on the X-ray Theory

My aim is to better compare thermoelasticity theory with a continuum theory of X-ray observations of crystals, to be described, to make it easier to adapt ideas and techniques from one to the other. To this end, I will present some different ways of formulating the X-ray theory. Also, I will adapt symmetry considerations from the former, partly to analyze problems of a kind not considered in thermoelasticity theory. This revised version was published online in August 2006 with corrections to the Cover Date.