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Nov 9, 2017 at 0:07 vote accept Mark.Neuhaus
Nov 9, 2017 at 0:06 vote accept Mark.Neuhaus
Nov 9, 2017 at 0:07
May 10, 2012 at 20:39 comment added Mike Shulman Even more geometrically, the twist isomorphism $S^n \wedge S^k \cong S^k \wedge S^n$ has degree $(-1)^{n k}$ under the identification of both sides with $S^{n+k}$.
May 10, 2012 at 12:59 answer added Jake timeline score: 8
May 10, 2012 at 11:54 answer added Vladimir Dotsenko timeline score: 4
May 10, 2012 at 11:15 comment added Mark Grant This is known as the Koszul sign convention. My guess (and it is only a guess) is that it has its origins in geometry: for a wedge of differential forms we have $\eta\wedge\omega = (-1)^{\operatorname{deg}(\omega)\operatorname{deg}(\eta)}\omega\wedge\eta$, which makes the exterior derivative well-behaved and keeps track of orientations.
May 10, 2012 at 10:55 history asked Mark.Neuhaus CC BY-SA 3.0