2017/11/10 by Galkowski, Jeffrey, Léautaud, Matthieu
#Analysis of PDEs (math.AP) #FOS: Mathematics #Spectral Theory (math.SP)
paper · doi:10.48550/arxiv.1711.03939
We consider a compact Riemannian manifold M (possibly with boundary) and Σ⊂ M∖ ∂ M an interior hypersurface (possibly with boundary). We study observation and control from Σ for both the wave and heat equations. For the wave equation, we prove controllability from Σ in time T under the assumption (TGCC) that all generalized bicharacteristics intersect Σ transversally in the time interval (0,T). For the heat equation we prove unconditional controllability from Σ. As a result, we obtain uniform lower bounds for the Cauchy data of Laplace eigenfunctions on Σ under TGCC and unconditional exponential lower bounds on such Cauchy data.