Metadata
Abstract
We establish small-time asymptotic expansions for heat kernels of hypoelliptic Hörmander operators in a neighborhood of the diagonal, generalizing former results obtained in particular by Métivier and by Ben Arous. The coefficients of our expansions are identified in terms of the nilpotentization of the underlying sub-Riemannian structure. Our approach is purely analytic and relies in particular on local and global subelliptic estimates as well as on the local nature of small-time asymptotics of heat kernels. The fact that our expansions are valid not only along the diagonal but in an asymptotic neighborhood of the diagonal is the main novelty, useful in view of deriving Weyl laws for subelliptic Laplacians. Incidentally, we establish a number of other results on hypoelliptic heat kernels that are interesting in themselves, such as Kac’s principle of not feeling the boundary, asymptotic results for singular perturbations of hypoelliptic operators, global smoothing properties for selfadjoint heat semigroups.
References
[ABB12] On the Hausdorff volume in sub-Riemannian geometry, Calc. Var. Partial Differ. Equ., Volume 43 (2012) no. 3-4, pp. 355-388 | DOI | MR | Zbl
[ABB20] A Comprehensive Introduction to Sub-Riemannian geometry. From the Hamiltonian viewpoint., Cambridge Studies in Advanced Mathematics, 181, Cambridge University Press, 2020 (with an appendix by Igor Zelenko) | Zbl
[ABGR09] The intrinsic hypoelliptic Laplacian and its heat kernel on unimodular Lie groups, J. Funct. Anal., Volume 256 (2009) no. 8, pp. 2621-2655 | DOI | MR | Zbl
[AM05] Rigid Carnot algebras: a classification, J. Dyn. Control Syst., Volume 11 (2005) no. 4, pp. 449-494 | DOI | MR | Zbl
[BA89] Développement asymptotique du noyau de la chaleur hypoelliptique sur la diagonale, Ann. Inst. Fourier, Volume 39 (1989) no. 1, pp. 73-99 | Numdam | MR | Zbl
[BAL91a] Décroissance exponentielle du noyau de la chaleur sur la diagonale. I, Probab. Theory Relat. Fields, Volume 90 (1991) no. 2, pp. 175-202 | DOI | MR | Zbl
[BAL91b] Décroissance exponentielle du noyau de la chaleur sur la diagonale. II, Probab. Theory Relat. Fields, Volume 90 (1991) no. 3, pp. 377-402 | DOI | MR | Zbl
[Bar13] Trace heat kernel asymptotics in 3D contact sub-Riemannian geometry, J. Math. Sci., New York, Volume 195 (2013) no. 3, pp. 391-411 Translation of Sovrem. Mat. Prilozh. No. 82 (2012) | DOI | MR | Zbl
[Bel96] The tangent space in sub-Riemannian geometry, Sub-Riemannian geometry. Proceedings of the satellite meeting of the 1st European congress of mathematics “Journées nonholonomes : géométrie sous-riemannienne, théorie du contrôle, robotique”, Paris, France, June 30–July 1, 1992 (Progress in Mathematics), Volume 144, Birkhäuser, 1996, pp. 1-78 | DOI | MR | Zbl
[Bon69] Principe du maximum, inégalité de Harnack et unicité du problème de Cauchy pour les opérateurs elliptiques dégénérés, Ann. Inst. Fourier, Volume 19 (1969) no. fasc. 1, pp. 277-304 | DOI | Numdam | MR | Zbl
[CdVHT] Spectral asymptotics for sub-Riemannian Laplacians (Work in progress) | Zbl
[CdVHT16] Quantum ergodicity and quantum limits for sub-Riemannian Laplacians, Sémin. Laurent Schwartz, EDP Appl., Volume 2014-2015 (2016), 20 | Zbl
[CdVHT18] Spectral asymptotics for sub-Riemannian Laplacians, I: Quantum ergodicity and quantum limits in the 3-dimensional contact case, Duke Math. J., Volume 167 (2018) no. 1, pp. 109-174 | DOI | MR | Zbl
[CGT82] Finite propagation speed, kernel estimates for functions of the Laplace operator, and the geometry of complete Riemannian manifolds, J. Differ. Geom., Volume 17 (1982) no. 1, pp. 15-53 | MR | Zbl
[CS08] Gaussian heat kernel upper bounds via the Phragmén–Lindelöf theorem, Proc. Lond. Math. Soc., Volume 96 (2008) no. 2, pp. 507-544 | DOI | MR | Zbl
[EH03] Spectral properties of hypoelliptic operators, Commun. Math. Phys., Volume 235 (2003) no. 2, pp. 233-253 | DOI | MR | Zbl
[EN00] One-parameter semigroups for linear evolution equations, Graduate Texts in Mathematics, 194, Springer, 2000 | MR | Zbl
[Fuk87] Collapsing of Riemannian manifolds and eigenvalues of Laplace operator, Invent. Math., Volume 87 (1987) no. 3, pp. 517-547 | DOI | MR | Zbl
[Ge93] Collapsing Riemannian metrics to Carnot–Carathéodory metrics and Laplacians to sub-Laplacians, Can. J. Math., Volume 45 (1993) no. 3, pp. 537-553 | DOI | MR | Zbl
[Gro96] Carnot–Carathéodory spaces seen from within, Sub-Riemannian geometry (Progress in Mathematics), Volume 144, Birkhäuser, 1996, pp. 79-323 | DOI | MR | Zbl
[HN05] Hypoelliptic estimates and spectral theory for Fokker–Planck operators and Witten Laplacians, Lecture Notes in Mathematics, 1862, Springer, 2005 | MR | Zbl
[Hsu95] On the principle of not feeling the boundary for diffusion processes, J. Lond. Math. Soc., Volume 51 (1995) no. 2, pp. 373-382 | DOI | MR | Zbl
[Hue60] Phénomènes de perturbation singulière dans les problèmes aux limites, Ann. Inst. Fourier, Volume 10 (1960), pp. 61-150 | DOI | Numdam | MR | Zbl
[Hör58] On the division of distributions by polynomials, Ark. Mat., Volume 3 (1958), pp. 555-568 | DOI | MR | Zbl
[Hör67] Hypoelliptic second order differential equations, Acta Math., Volume 119 (1967), pp. 147-171 | DOI | MR | Zbl
[Jea14] Control of nonholonomic systems: from sub-Riemannian geometry to motion planning, SpringerBriefs in Mathematics, Springer, 2014 | DOI | MR | Zbl
[JSC86] Estimates for the heat kernel for a sum of squares of vector fields, Indiana Univ. Math. J., Volume 35 (1986) no. 4, pp. 835-854 | DOI | MR | Zbl
[Kan77] Off diagonal short time asymptotics for fundamental solutions of diffusion equations, Commun. Partial Differ. Equations, Volume 2 (1977) no. 8, pp. 781-830 | DOI | MR | Zbl
[Koh73] Pseudo-differential operators and hypoellipticity, Partial differential equations. Univ. California, Berkeley, Calif., 1971) (Proceedings of Symposia in Applied Mathematics), Volume 23, American Mathematical Society, 1973, pp. 61-69 | MR | Zbl
[KS88] Long time estimates for the heat kernel associated with a uniformly subelliptic symmetric second order operator, Ann. Math., Volume 127 (1988) no. 1, pp. 165-189 | DOI | MR | Zbl
[LD10] Lecture Notes on sub-Riemannian geometry, 2010 (Ongoing work, preprint)
[Lio73] Perturbations singulières dans les problèmes aux limites et en contrôle optimal, Lecture Notes in Mathematics, 323, Springer, 1973 | MR | Zbl
[Mah98] Estimations du noyau de la chaleur sur les espaces homogènes, J. Geom. Anal., Volume 8 (1998) no. 1, pp. 65-96 | DOI | MR | Zbl
[Mar07] Classification of Carnot algebras: the semi-rigid cases, J. Dyn. Control Syst., Volume 13 (2007) no. 1, pp. 95-119 | DOI | MR | Zbl
[Mel85] The wave equation for a hypoelliptic operator with symplectic characteristics of codimension two, J. Anal. Math., Volume 44 (1984/85), pp. 134-182 | DOI | MR | Zbl
[Mon02] A tour of subriemannian geometries, their geodesics and applications, Mathematical Surveys and Monographs, 91, American Mathematical Society, 2002 | MR | Zbl
[MS78] On the eigenvalues of a class of hypoelliptic operators, Math. Ann., Volume 235 (1978) no. 1, pp. 55-85 | DOI | MR | Zbl
[Mét76] Fonction spectrale et valeurs propres d’une classe d’opérateurs non elliptiques, Commun. Partial Differ. Equations, Volume 1 (1976) no. 5, pp. 467-519 | DOI | MR | Zbl
[Paz83] Semigroups of linear operators and applications to partial differential equations, Applied Mathematical Sciences, 44, Springer, 1983 | DOI | MR | Zbl
[Rif14] Sub-Riemannian geometry and optimal transport, SpringerBriefs in Mathematics, Springer, 2014 | DOI | MR | Zbl
[Rum00] Sub-Riemannian limit of the differential form spectrum of contact manifolds, Geom. Funct. Anal., Volume 10 (2000) no. 2, pp. 407-452 | DOI | MR | Zbl
[SC84] Fundamental solutions and geometry of the sum of squares of vector fields, Invent. Math., Volume 78 (1984) no. 1, pp. 143-160 | DOI | MR | Zbl
[SC92] A note on Poincaré, Sobolev, and Harnack inequalities, Int. Math. Res. Not. (1992) no. 2, pp. 27-38 | DOI | MR | Zbl
[Str86] Sub-Riemannian geometry, J. Differ. Geom., Volume 24 (1986) no. 2, pp. 221-263 | MR | Zbl
[Var90] Small time Gaussian estimates of heat diffusion kernels. II. The theory of large deviations, J. Funct. Anal., Volume 93 (1990) no. 1, pp. 1-33 | DOI | MR | Zbl