Indefinite Form
There are as many as eight different double covers of O(p, q), for p, q ≠ 0, which correspond to the extensions of the center (which is either C2 × C2 or C4) by C2. Only two of them are pin groups—those that admit the Clifford algebra as a representation. They are called Pin(p, q) and Pin(q, p) respectively.
Read more about this topic: Pin Group
Famous quotes containing the words indefinite and/or form:
“... indefinite visions of ambition are weak against the ease of doing what is habitual or beguilingly agreeable.”
—George Eliot [Mary Ann (or Marian)
“Shopping seemed to take an entirely too important place in women’s lives. You never saw men milling around in men’s departments. They made quick work of it. I used to wonder if shopping was a form of escape for women who had no worthwhile interests.”
—Mary Barnett Gilson (1877–?)