8,041 reputation
1643
bio website people.bath.ac.uk/mdp33
location Bath, United Kingdom
age 25
visits member for 2 years, 6 months
seen Aug 11 at 15:14

Postgraduate student at the University of Bath, UK, studying geometry and representation theory. Currently thinking about cluster algebras and related objects.


Jul
15
revised Is a norm on $R^n$ linear?
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Jul
15
answered Is a norm on $R^n$ linear?
Jul
15
revised What is $\operatorname{Ass}\operatorname{Ext}^i(M,N)$?
added 145 characters in body; edited title
Jul
11
comment If $A$ is compact and connected, then is $\Bbb R^2\setminus A$ connected?
It's not really a stupid question! But the lesson should probably be to always try out some examples first - Heine-Borel makes it fairly easy to generate lots of them. (Of course, if you didn't have a good handle on what it means to be compact, then generating example might be more problematic, but it seems that you do.)
Jul
11
comment How Max plus algebra is different from conventional algebra?
In a sense, your tag provides an answer to the question - the max-plus algebra gives us a neat way to tropicalize a variety, and then there are various theorems relating properties of the original variety to properties of the tropical variety, which are potentially easier to compute because of the combinatorial nature of the object. I believe there are other applications of max-plus not directly to do with tropical geometry, but I don't know what they are.
Jul
10
comment writing papers: definition in word or formula?
This question might be too opinion-based. I don't have any real preference between the three options. If the set had a more complicated definition, then I would probably be more strongly against C) and more strongly in favour of A). The aim should always be clarity, but this can be extremely subjective.
Jul
10
reviewed Approve suggested edit on writing papers: definition in word or formula?
Jul
1
revised If a voronoi vertex q is an endpoint of a voronoi edge l, then the delaunay polygon dual to q has a delaunay edge dual to l as one of its edges.
added 164 characters in body
Jul
1
revised Counting the number of zeros
edited tags
Jun
26
answered Origin in homogeneous coordinates
Jun
26
comment Origin in homogeneous coordinates
@HaraldHanche-Olsen Standard that may be, but canonical it is not! ;-)
Jun
26
comment Origin in homogeneous coordinates
To elaborate a little - the origin of a vector space is special because it is the additive identity under the group structure. But once you projectivise the vector space, the group structure disappears - and there is no "special" line in the vector space to play the role of the origin in projective space.
Jun
26
comment Origin in homogeneous coordinates
There is no origin in projective space!
Jun
26
comment Building quotient rings
@o2genum I'm not sure this is a concrete question - you already have described the rings! If you want to describe them in another form, you need to be quite specific about what that form should be. Asking whether the first two are isomorphic to $\mathbb{Z}_n$ is a perfectly good question, but "what ring is $\mathbb{Z}[\sqrt{-2}]/(2)$ isomorphic to?" is too open-ended (unless there's a "standard" ring it's isomorphic to that I don't immediately see).
Jun
19
reviewed Approve suggested edit on If $λ \neq 0$ an eigenvalue of matrix $A$ then find an eigenvalue of $\text{adj}\left(A\right)$
Jun
19
comment Is it true that every eigenvalue has at least one eigenvector?
You could in theory define an eigenvalue to be a root of the characteristic polynomial of $f$. Michael's answer provides half of the proof that these two definitions are equivalent.
Jun
17
comment Is the intersection of dense sets dense?
@freebird The complement of a nowhere dense set is always dense - indeed, one definition of a nowhere dense is that the complement of its closure is dense. But the complement of a dense set is not necessarily nowhere dense, as in the example in your question. So you while you can't prove that the intersection of two arbitrary dense sets is dense (because this is false!) the sets $A'$ and $B'$ in your setup have the stronger property that their complements $A$ and $B$ are nowhere dense. I agree with Ittay that this is probably not the best way to think about the problem though.
Jun
16
answered Is $M=\{\frac{1}{k}|k \in \mathbb{N}\}$ closed?
Jun
9
revised Why is $\left( \begin{smallmatrix} x & y \\ y & t \\ \end{smallmatrix} \right)$ orthogonally similar to this?
deleted 40 characters in body; edited title
Jun
9
answered Formalize definition of subbase of a topology