Topics include: structural results about, and classifying the preservers of positive semidefiniteness and other Loewner properties (monotonicity, convexity, super-additivity); historical connections ...

Data Preservers The anniversaries of 9/11 and Hurricane Katrina have passed. The hottest summer in recent memory, the cause of prolonged East Coast power outages, is finally over.

Topics include: structural results about, and classifying the preservers of positive semidefiniteness and other Loewner properties (monotonicity, convexity, super-additivity); historical connections ...