New methods for old spaces: synthetic differential geometry
arXiv:1610.00286
Abstract
Survey talk on certain aspects of the subject, stressing the neighbor relation as a basic notion in differential geometry.
Invited contribution to the planned book: New Spaces in Mathematics and Physics - Formal and Philosophical Reflections (ed. M. Anel and G. Cartren), presented at the Workshop at IHP (Paris), September 28 - October 2 2015. Updated Sept. 2017, including a section on Huygens' principle of wave fronts