Sure, you can delete text messages, @Symposium. What doesn't work is sending one, realizing you sent it to the wrong person, and then trying to delete it on your end to "unsend" it.
@LeakyNun Because WhatsApp is basically iMessage service (wifi/internet based). I'm pretty sure they use different wave signals or something to normal texts!
@Leaky I think I sorted that thing earlier; I can send $f$ to $\varphi \circ f \circ \varphi^{-1}$ and this should be an isomorphism with an obvious inverse
@TedShifrin then $GL_n(R)$ can be identified with $\operatorname{Hom}(\Bbb Z[X_{11}, \cdots, X_{nn}, T]/(pT-1), R)$ by some universal properties of quotients and polynomial rings
@TedShifrin Interesting. That sounds like the app Signal; the one where all the criminals moved to after it turned out the feds had a backdoor to WhatsApp.
I guess you should state stuff in a sophisticated manner, but be prepared to back up and fill in details. Also, as I said to Alessandro, I'm a big believer that you should have interesting examples, not just abstraction.
Hmm, I may think about that at some point. At the moment I'm a bit busy because I'm trying to read around a bunch of stuff and ideally have a topic idea (at least to start with) next week
@Symposium I'm not sure actually. I would like number theory, representation theory or noncommutative algebra. Of those three, number theory seems the most probable right now, as that is what a lot of pros here in Heidelberg do.
Is this definition correct? $B_n$ is the unit open ball in $\mathbb{R}^n,$ with its center at $\vec{x}$, defined as: $B_n := \{\vec{y} : |\vec{y} - \vec{x}| < 1 \}$
