Signature Change
If a metric is regular everywhere then the signature of the metric is constant. However if one allows for metrics that are degenerate or discontinuous on some hypersurfaces, then signature of the metric may change at these surfaces. Such signature changing metrics may possibly have applications in cosmology and quantum gravity.
Read more about this topic: Metric Signature
Famous quotes containing the words signature and/or change:
“The childless experts on child raising also bring tears of laughter to my eyes when they say, “I love children because they’re so honest.” There is not an agent in the CIA or the KGB who knows how to conceal the theft of food, how to fake being asleep, or how to forge a parent’s signature like a child.”
—Bill Cosby (20th century)
“In the continual enterprise of trying to guide appropriately, renegotiate with, listen to and just generally coexist with our teenage children, we ourselves are changed. We learn even more clearly what our base-line virtues are. We listen to our teenagers and change our minds about some things, stretching our own limits. We learn our own capacity for flexibility, firmness and endurance.”
—Jean Jacobs Speizer. Ourselves and Our Children, by Boston Women’s Health Collective, ch. 4 (1978)