bio  website  web.mat.bham.ac.uk/~barberba 

location  Birmingham, UK  
age  
visits  member for  3 years, 1 month 
seen  4 hours ago  
stats  profile views  779 
Postdoc in Birmingham with Daniela Kühn.
1d

reviewed  No Action Needed Kan extensions of pseudofunctors 
Aug
30 
comment 
What characteristic of a graph depend on the vertex labeling?
People have looked at Ramsey theory for graphs with an ordering of their vertices, although this is more looking at a new class of objects than a property of graphs that depends on some choice of vertex ordering. 
Aug
30 
reviewed  No Action Needed Can we drop commutativity assumption? 
Aug
30 
reviewed  No Action Needed Intuition for the tensor algebra? 
Aug
24 
reviewed  Close Annihilators of elements in symmetric algebras 
Aug
23 
comment 
Can every permutation group be realized as the automorphism group of a graph (acting on a subset of the vertices)?
Here's an extremely similar construction that no longer merits its own answer. As usual I'll state the labelled version. Start with the full Cayley graph $\Gamma$ of $P$; $P$ acts on $V(\Gamma) = P$ by $\pi(\rho) = \pi \rho$. Form the complete bipartite graph between $P$ and $X$. The group action has to be encoded somewhere, so label each edge $(\pi, x)$ by $\pi^{1}(x)$. I think that this works as required. It would be very interesting to see a construction that does not essentially pass through the Cayley graph. 
Aug
23 
reviewed  Approve Does every manifold have a flat connection? 
Aug
23 
reviewed  Reject Catalan numbers as sums of squares of numbers in the rows of the Catalan triangle  is there a combinatorial explanation? 
Aug
20 
comment 
Area defined with $\pm$ closedness
@KevinP.Costello Perhaps there is no point at maximal distance from the origin? 
Aug
17 
reviewed  No Action Needed Largest eigenvalues distribution of tridiagonal symmetric random matrix 
Aug
17 
comment 
Can we estimate the probability $\mathbf{P}(aka  b) $ on a random graph?
Do you know anything about the values of the $p_{uv}$? This is likely to be extremely difficult in full generality, but straightforward for many particular examples. For instance, if the $p_{uv}$ are constant and $G$ is large then all of your expressions are approximately equal to $1$ as $G$ is very likely to be connected. 
Aug
17 
reviewed  No Action Needed Gagliardo Nirenberg inequality for the laplacian 
Aug
17 
reviewed  Approve Gagliardo Nirenberg inequality for the laplacian 
Aug
14 
reviewed  No Action Needed Is there any theory of HamiltonJacobi system? 
Aug
13 
comment 
Maximal Number of Pairs of Orthogonal vectors in a set of $n$ vectors in $\mathbb{R}^3$
Following the comments, perhaps you could clarify whether or not the pairs are ordered? 
Aug
12 
comment 
Kissing number and overlapping number
Is it obvious that the overlapping number cannot exceed the kissing number no matter how strange the family $S$? 
Aug
12 
reviewed  No Action Needed How can I show that “almost all function” have property P? 
Aug
11 
reviewed  Reviewed A problem upon function series 
Aug
8 
awarded  co.combinatorics 
Aug
4 
reviewed  No Action Needed Quadratic variation for discrete Martingale 