MathOverflow

Let $P \in M_n(\mathbb{C})$ be a rank $k$ orthogonal projection, $k \geq 2$, and let $A_1, \ldots, A_r \in M_n(\mathbb{C})$ be matrices. Suppose that for every rank $k - 1$ orthogonal projection $Q < P$ there exists $i$ such that $Q + A_i$ is invertible...

Let $(M,g)$ be a pseudo-Riemannian spin manifold and let us denote by $S$ the spinor bundle, i.e. the associated vector bundle with respect to the spin representation. Usually, the "gamma matrices" are defined to be maps of the form$$\gamma:TM\to\mathrm...

On paper A procedure for improving the upper boundfor the number of $n$-ominoes by D. A. Klarner & R. L. Rivest, it is known that the number $t(n)$ of polyominoes with area $n$ satisfies $3.72^n<t(n)<6.75^n$.What is the best current result...

I am trying to calculate the three-term connection coefficients
$$Λ_{l,m}^{d_1,d_2,d_3} = \int_{-\infty}^\infty \varphi^{(d_1)}(x) \varphi^{(d_2)}_l(x) \varphi^{(d_3)}_m(x) dx$$
for Daubechies wavelets numerically using Python. This report (p. 20) gives a nice overview of how to calculate them....