2:04 AM
Is there a way to send a private message to a particular user on mathoverflow ?

4 hours later…
6:22 AM
5

Occasionally it might happen that I want to contact some user, although the thing I want to say is not directly relevant to one of their posts - which makes me think that this would be not really suitable for a comment under one of their post (where they would be notified). What can be done in si...

There isn't really something like private messages - if you choose any of the above options, it will be also visible to other people.
7

One convenient thing on AoPS that is missing on MO is the private message system where you can send and receive private messages to other users without figuring out who they are outside the internet and what is their e-mail, etc., or full disclosure of who you are yourself. The situations where y...

633

There has been quite a few times that I wished I could send a message to another user on SO - not ask a question for everyone to see, but just a short message informing them of something or requesting them to do something. Are there any plans to allow this to happen in the future? Related: How ...

11 hours later…
5:52 PM
2

Consider the following fragments from "An invitation to quantum groups and duality" by Timmerman: Question: In remark 2.1.6 (ii), it is stated that the homomorphism $\Delta\otimes \text{id}: A \otimes A \to A \otimes A \otimes A$ is extended to a homomorphism $M(A \otimes A) \to M(A \otimes A \o... 2 Consider the following definitions given in Timmerman's book "An invitation to quantum groups and duality": m Further in the book, it is claimed that if$A$and$B$are non-degenerate algebras, then we have a canonical inclusion$M(A)\otimes M(B)\hookrightarrow M(A\otimes B)\$. How exactly does t...

In mathematics, the multiplier algebra, denoted by M(A), of a C*-algebra A is a unital C*-algebra which is the largest unital C*-algebra that contains A as an ideal in a "non-degenerate" way. It is the noncommutative generalization of Stone–Čech compactification. Multiplier algebras were introduced by Busby (1968). For example, if A is the C*-algebra of compact operators on a separable Hilbert space, M(A) is B(H), the C*-algebra of all bounded operators on H. == Definition == An ideal I in a C*-algebra B is said to be essential if I ∩ J is non-trivial for all ideal J. An ideal I is essential if...