Skip to main content

Timeline for The advantage of asymmetric objects

Current License: CC BY-SA 4.0

13 events
when toggle format what by license comment
Jul 1, 2022 at 21:06 review Close votes
Jul 3, 2022 at 5:52
Jul 1, 2022 at 18:47 answer added Vladimir Dotsenko timeline score: 3
Jul 1, 2022 at 17:43 comment added Maxime Ramzi When an object has no automorphism, it is typically quite simple to prove that some other object is isomorphic to it (if it is, of course): there is only one possible choice of isomorphism, so you can't go wrong ! In another direction, bundles of objects with no automorphisms are trivial - for instance any manifold is $\mathbb Z/2$-orientable
Jul 1, 2022 at 16:15 history edited Glorfindel CC BY-SA 4.0
edited body
Jul 1, 2022 at 4:21 comment added Michael Engelhardt @LSpice - At its core, I think all that was meant was that the symmetrized object does not reveal what the symmetry does, being invariant under the symmetry. You have to pick a representative to see it. Simple as that is, it can take interesting guises. E.g., the most direct understanding of the rotating rigid body is in the body-fixed frame; viscerally, you have to get on the merry-go-round to fully experience it. In a gauge theory, physical degrees of freedom only become evident upon fixing a gauge (e.g., the Coulomb gauge in classical electrodynamics, which renders the waves transverse).
Jul 1, 2022 at 1:48 comment added LSpice @MichaelEngelhardt, do you have any interesting examples of putting that aphorism into practice? (I suspect my thoughts on it are shallower than those of someone who thinks about it professionally, so I'd like to hear yours!)
Jul 1, 2022 at 1:13 comment added Michael Engelhardt One of the aphorisms I remember from one of my mentors is, "Everything we've ever learned about symmetries we learned by breaking them. Think about it."
Jul 1, 2022 at 0:42 history became hot network question
Jul 1, 2022 at 0:40 history edited Veronica Phan CC BY-SA 4.0
added 13 characters in body
Jul 1, 2022 at 0:17 comment added LSpice Asymmetric objects in your sense are often called rigid. One nice (almost-)example is algebraic tori, which have no connected algebraic group of automorphisms.
Jun 30, 2022 at 23:33 answer added Timothy Chow timeline score: 12
Jun 30, 2022 at 17:23 answer added Peter LeFanu Lumsdaine timeline score: 22
Jun 30, 2022 at 16:42 history asked Veronica Phan CC BY-SA 4.0