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Mar 19, 2022 at 17:24 history edited YCor CC BY-SA 4.0
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Dec 23, 2017 at 17:30 comment added Majid @AntonPetrunin Is there any reference that I can refer to?
Dec 23, 2017 at 17:29 comment added Majid @AntonPetrunin what do you mean by the most important property of angle and use it as the definition? The only thing that I know is that the angle is the cos^-1 or sin^-1 of the inner product or exterior product divided by the norms!
Dec 20, 2017 at 22:11 comment added Majid @AntonPetrunin if you are talking about my case, no. If you are talking about some definition of angle, I do not know. My problem is that I saw through some examples that the angle between two special vector fields is constant along a submanifold. I am suspected that it is true is general case of my problem and so I needed to define the angle.
Dec 20, 2017 at 20:15 comment added Anton Petrunin @Majid, is not it the first variation formula if you move in the direction $v$ and measure the distances to a point in the direction $w$?
Dec 20, 2017 at 19:43 comment added user44143 I agree with @AntonPetrunin. Following Busemann, I would also say: do you need vectors? Perhaps define the angle at $p$ between curves $a$ and $b$ as $2 \lim \arcsin d(a_s, b_s)/2s$, where $a_s$ and $b_s$ are the points at distance $s$ from $p$ along the curves.
Dec 20, 2017 at 19:39 comment added Majid @AntonPetrunin You mentioned that different properties lead to different definitions. Is there any property which leads to my second definition?
Dec 20, 2017 at 19:38 comment added Majid @AntonPetrunin I need the angle in the case of Finsler since I am trying to show that the angle between two special vectors remain constant along a submanifold. Could you please give me some reference where the angle in Riamannian is defined. You mentioned that the one that I defined looks OK. Which one? I have defined two.
Dec 20, 2017 at 18:57 comment added Anton Petrunin I doubt that you need angle in Finsler space. If you insist, then look at Riemannian case, choose the most important property of angle and use it as the definition --- typically different properties lead to different definitions. The one you propose looks okey, it is not symmetric, but you always have to sacrifice something in the Finsler world.
Dec 20, 2017 at 17:24 history asked Majid CC BY-SA 3.0