bio  website  web.mit.edu/abhinavk/www 

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2d

awarded  Yearling 
Nov 27 
reviewed  Approve Isomorphism problem for two radical extensions 
Nov 26 
reviewed  Approve Simplifying triangulations of 3manifolds 
Oct 9 
answered  When the contraction is a morphism defined over $\overline{\mathbb Q}$ 
Jul 31 
comment 
K3 surfaces that correspond to rational points of elliptic curves
@LevBorisov Are you aware of the work of Kudla and recent work of Darmon and others? It might have some connection to what you're looking for. 
Jul 30 
comment 
K3 surfaces that correspond to rational points of elliptic curves
The field of definition of the point $P$ on $X_0(n)^+$ should probably correspond to the field of the definition of the corresponding divisor on the K3 surface. So saying that it comes from a $\bf{Q}$ point just means that the Picard group of the K3 can be fully realized over a small degree number field (here, probably the $2$torsion field of the elliptic curves). 
Jul 30 
comment 
K3 surfaces that correspond to rational points of elliptic curves
It seems that the K3 is not the Kummer, but is is a double cover (i.e. related by a ShiodaInose structure to the product abelian surface). See theorem 7.6 of that paper. 
May 9 
comment 
Elliptic surfaces with different Kodaira symbols
At least in characteristic not 2 or 3 this is impossible: the elliptic fibration is unique for Kodaira dimension 1. For char 2 or 3 you may have to consider quasielliptic fibrations, and I haven't thought through it. 
May 8 
answered  Lattice polarized K3 surfaces 
May 8 
comment 
Lattice polarized K3 surfaces
No, the Picard rank can be anywhere between 1 and 20, for a lattice polarized K3 surface. 
Mar 28 
reviewed  Approve On a particular case of the ``TumuraHayman" theorem : 
Jan 30 
reviewed  Reject Cohomology after completion 
Jan 16 
comment 
Commutativity of convex hulls and closed balls
I believe I now have a counterexample  see above. 
Jan 16 
revised 
Commutativity of convex hulls and closed balls
added 1351 characters in body 
Jan 15 
answered  Commutativity of convex hulls and closed balls 
Jan 14 
awarded  Good Question 
Jan 12 
awarded  Custodian 
Jan 12 
reviewed  Approve Distribution of moduli of quadratic residues 
Jan 2 
comment 
Determinant and eigenvalues of a specific matrix
If you let $e^{c}$ be $x$, then the matrix has polynomial entries in $x$, and experiment seems to indicate that the determinant is a product of cyclotomic polynomials (for instance, if $n = 6$, we get $(x1)^{15}(x+1)^{15}(x^2+1)^6 (x^2x+1)^3(x^2+x+1)^3(x^4+1)^2(x^4x^3+x^2x+1)(x^4+x^3+x^2+x+1)$. (In particular, the power of $(x \pm 1)$ seems to be $n$ choose $2$.) 
Dec 19 
awarded  Yearling 