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)
“The phenomena of the year take place every day in a pond on a small scale. Every morning, generally speaking, the shallow water is being warmed more rapidly than the deep, though it may not be made so warm after all, and every evening it is being cooled more rapidly until the morning. The day is an epitome of the year. The night is the winter, the morning and evening are the spring and fall, and the noon is the summer. The cracking and booming of the ice indicate a change of temperature.”
—Henry David Thoreau (1817–1862)