The eigenvalues of hypoelliptic operators
Journées équations aux dérivées partielles (1977), pp. 157-163. 
@article{JEDP_1977____157_0,
     author = {Menikoff, A. and Sj\"ostrand, Johannes},
     title = {The eigenvalues of hypoelliptic operators},
     journal = {Journ\'ees \'equations aux d\'eriv\'ees partielles},
     pages = {157--163},
     publisher = {Ecole polytechnique},
     year = {1977},
     language = {en},
     url = {http://www.numdam.org/item/JEDP_1977____157_0/}
}
TY  - JOUR
AU  - Menikoff, A.
AU  - Sjöstrand, Johannes
TI  - The eigenvalues of hypoelliptic operators
JO  - Journées équations aux dérivées partielles
PY  - 1977
SP  - 157
EP  - 163
PB  - Ecole polytechnique
UR  - http://www.numdam.org/item/JEDP_1977____157_0/
LA  - en
ID  - JEDP_1977____157_0
ER  - 
%0 Journal Article
%A Menikoff, A.
%A Sjöstrand, Johannes
%T The eigenvalues of hypoelliptic operators
%J Journées équations aux dérivées partielles
%D 1977
%P 157-163
%I Ecole polytechnique
%U http://www.numdam.org/item/JEDP_1977____157_0/
%G en
%F JEDP_1977____157_0
Menikoff, A.; Sjöstrand, Johannes. The eigenvalues of hypoelliptic operators. Journées équations aux dérivées partielles (1977), pp. 157-163. http://www.numdam.org/item/JEDP_1977____157_0/

[1] S. Agmon and Y. Kannai. On the asymptotic behavior of the spectral functions and resolvent kernels of elliptic operators. Israel J. Math. 5 (1967) 1-30. | MR | Zbl

[2] C. Bolley, J. Camus and T. Pham. In this volume.

[3] L. Boutet De Monvel and F. Treves. On a classe of pseudo-differential operators with double characteristics. Invent. Math. 24 (1974) 1-34. | MR | Zbl

[4] L. Hörmander. The spectral function of an elliptic operator. Acta Math. 121 (1968) 193-218. | MR | Zbl

[5] A. Melin. Lower bounds for pseudo-differential operators. Ark. Mat. 9 (1971) 117-140. | MR | Zbl

[6] A. Melin and J. Sjöstrand. Fourier integral operators with complex-valued phase functions. Springer L.N. 459, 255-282. | Zbl

[7] G. Metivier. Fonction spectrale et valeurs propres d'une classe d'opérateurs non elliptiques. Comm. PDE 1 (1976) 467-519. | MR | Zbl

[8] R. Seeley. Complex powers of an elliptic operator. AMS Proc. Symp. in Pure Math. 10 (1967) 288-307. | MR | Zbl

[9] J. Sjöstrand. Parametrices for pseudodifferential operators with multiple characteristics. Ark. Mat. 12 (1974) 85-130. | MR | Zbl