We give an example of a domain in dimension N ≤ 3, homeomorphic to a ball and with analytic boundary, for which the second eigenvalue of the Dirichlet Laplacian has an eigenfunction with a closed ...

A classical Reye congruence X is an Enriques surface of rational equivalence class (3, 7) in the grassmannian G(1, 3) of lines of P3. X is the locus of lines of P3 which are included in two quadrics ...

Metamaterial sound proofing from materials less than an inch thick would be as good as 4 foot thick walls for soundproofing. People outside a metamaterial sound proofed room – no one will hear you ...