Dylan P. Thurston | Akateeminen Kirjakauppa

Let $X$ be an abstract not necessarily compact orientable CR manifold of dimension $2n-1$, $ngeqslant 2$, and let $L^k$ be the $k$-th tensor power of a CR complex line bundle $L$ over $X$. Given $qin {0,1,ldots ,n-1}$, let $Box ^{(q)}_{b,k}$ be the Gaffney extension of Kohn Laplacian for $(0,q)$ forms with values in $L^k$. For $lambda geq 0$, let $Pi ^{(q)}_{k,leq lambda} :=E((-infty ,lambda ])$, where $E$ denotes the spectral measure of $Box ^{(q)}_{b,k}$. In this work, the author proves that $Pi ^{(q)}_{k,leq k^{-N_0}}F^*_k$, $F_kPi ^{(q)}_{k,leq k^{-N_0}}F^*_k$, $N_0geq 1$, admit asymptotic expansions with respect to $k$ on the non-degenerate part of the characteristic manifold of $Box ^{(q)}_{b,k}$, where $F_k$ is some kind of microlocal cut-off function. Moreover, we show that $F_kPi ^{(q)}_{k,leq 0}F^*_k$ admits a full asymptotic expansion with respect to $k$ if $Box ^{(q)}_{b,k}$ has small spectral gap property with respect to $F_k$ and $Pi^{(q)}_{k,leq 0}$ is $k$-negligible away the diagonal with respect to $F_k$. By using these asymptotics, the authors establish almost Kodaira embedding theorems on CR manifolds and Kodaira embedding theorems on CR manifolds with transversal CR $S^1$ action.