No Arabic abstract
We study the asymptotics of the Poisson kernel and Greens functions of the fractional conformal Laplacian for conformal infinities of asymptotically hyperbolic manifolds. We derive sharp expansions of the Poisson kernel and Greens functions of the conformal Laplacian near their singularities. Our expansions of the Greens functions answer the first part of the conjecture of Kim-Musso-Wei[22] in the case of locally flat conformal infinities of Poincare-Einstein manifolds and together with the Poisson kernel asymptotic is used also in our paper [25] to show solvability of the fractional Yamabe problem in that case. Our asymptotics of the Greens functions on the general case of conformal infinities of asymptotically hyperbolic space is used also in [30] to show solvability of the fractional Yamabe problem for conformal infinities of dimension $3$ and fractional parameter in $(frac{1}{2} , 1)$ to a global case left by previous works.
We show that zero is not an eigenvalue of the conformal Laplacian for generic Riemannian metrics. We also discuss non-compactness for sequences of metrics with growing number of negative eigenvalues of the conformal Laplacian.
In this paper, we study the asymptotics of Ohsawa-Takegoshi extension operator and orthogonal Bergman projector associated with high tensor powers of a positive line bundle. More precisely, for a fixed submanifold in a complex manifold, we consider the operator which associates to a given holomorphic section of a positive line bundle over the submanifold the holomorphic extension of it to the ambient manifold with the minimal $L^2$-norm. When the tensor power of the line bundle tends to infinity, we prove an exponential estimate for the Schwartz kernel of this extension operator, and show that it admits a full asymptotic expansion in powers of the line bundle. Similarly, we study the asymptotics of the orthogonal Bergman kernel associated to the projection onto the holomorphic sections orthogonal to those which vanish along the submanifold. All our results are stated in the setting of manifolds and embeddings of bounded geometry.
We study a fractional conformal curvature flow on the standard unit sphere and prove a perturbation result of the fractional Nirenberg problem with fractional exponent $sigma in (1/2,1)$. This extends the result of Chen-Xu (Invent. Math. 187, no. 2, 395-506, 2012) for the scalar curvature flow on the standard unit sphere.
The authors use Riemann-Hilbert methods to compute the constant that arises in the asymptotic behavior of the Airy-kernel determinant of random matrix theory.
We study the spatial asymptotics of Greens function for the 1d Schrodinger operator with operator-valued decaying potential. The bounds on the entropy of the spectral measures are obtained. They are used to establish the presence of a.c. spectrum