149,095 reputation
595247
bio website math.ubc.ca/~israel
location Richmond, Canada
age
visits member for 3 years, 10 months
seen 3 mins ago

I'm an Emeritus Associate Professor of Mathematics at University of British Columbia and an Optimization Algorithms Researcher at D-Wave Systems in Burnaby BC


3h
comment Finding Eigenvalues of given linear operator
... and solve a differential equation.
4h
answered Uniform convergence to 0
4h
comment Understanding Overdetermined System
Because one $(x_1,x_2)$ value satisfies all the equations.
12h
answered Contour Integration where Contour contains singularity
12h
answered If $X + X^T$ is positive definite, is $X^{-1} + X^{-T}$ also positive definite?
12h
comment about a sequence of isometries' convergency.
The $x_m$ could all be the same. If you just need the convergence to be pointwise rather than uniform, you can take them all to be the same.
13h
answered Rank of block matrix
18h
answered Given a square matrix where $a_{11}=c\neq 0$ and $a_{ij}=0$ otherwise, can we find a matrix B such that B and A+B have no common eigenvalues?
18h
comment Find the $n$ for which $σ(n) = 15$
When you eliminate all other possibilities, the one remaining is unique.
18h
comment Find the $n$ for which $σ(n) = 15$
@Sasha you mean $\sigma(n) \ge n + 1$.
18h
answered about a sequence of isometries' convergency.
21h
answered existence of a borel probability measure on $[0,1]$ such that $\int f d\mu=\lim_{k\to\infty}\frac {1} {N_k} \sum_{i=1}^{N_k}f(x_i)$ given sequence
22h
comment 'Rational' solutions of sine
$2 \sin(\pi r) = -i \exp(i\pi r) + i \exp(-i \pi r)$. $\pm i$ and $\exp(\pm i \pi r)$ are algebraic integers, being roots of unity. The sum or product of algebraic integers is an algebraic integer.
22h
answered 'Rational' solutions of sine
22h
answered Solve the following matrix equation $X'X=A$
1d
awarded  Enlightened
1d
awarded  Nice Answer
1d
answered weak -star topology on ball M[0,1]
1d
awarded  Enlightened
1d
answered Matching Algorithm in Graph Theory