We show that if $ u $ solves the fractional parabolic equation $ (\partial_t - \Delta )^s u = Vu $ in $ B_5 \times (-25, 0] $ ($ 0<s<1 $) such that $ u(\cdot, 0) \not\equiv 0 $, then the maximal vanishing order of $ u $ in space-time at $ (0, 0) $ is upper bounded by $ C\left(1+\|V\|_{C^{1}_{(x, t)}}^{1/2s}\right) $. As $ s \to 1 $, it converges to the sharp maximal order of vanishing due to Donnelly-Fefferman and Bakri. This quantifies a space-like strong unique continuation result recently proved in [3]. The proof is achieved by means of a new quantitative Carleman estimate that we derive for the corresponding extension problem combined with a quantitative monotonicity in time result and a compactness argument.
| Citation: |
| [1] |
V. Arya and A. Banerjee, Quantitative uniqueness for fractional heat type operators, Calc. Var. Partial Differential Equations, 62 (2023), Paper No. 195, 47 pp.
doi: 10.1007/s00526-023-02535-1.
|
| [2] |
V. Arya and A. Banerjee, Space like quantitative uniqueness for parabolic operators, J. Math. Pures Appl., 177 (2023), 214-259.
doi: 10.1016/j.matpur.2023.06.014.
|
| [3] |
V. Arya, A. Banerjee, D. Danielli and N. Garofalo, Space-like strong unique continuation for some fractional parabolic equations, J. Funct. Anal., 284 (2023), Paper No. 109723, 38 pp.
doi: 10.1016/j.jfa.2022.109723.
|
| [4] |
A. Audrito and S. Terracini, On the nodal set of solutions to a class of nonlocal parabolic reaction-diffusion equations, arXiv: 1807.10135, to appear in Memoirs of AMS.
|
| [5] |
L. Bakri, Quantitative uniqueness for Schrödinger operator, Indiana Univ. Math. J., 61 (2012), 1565-1580.
doi: 10.1512/iumj.2012.61.4713.
|
| [6] |
A. Banerjee and N. Garofalo, Monotonicity of generalized frequencies and the strong unique continuation property for fractional parabolic equations, Adv. Math., 336 (2018), 149-241.
doi: 10.1016/j.aim.2018.07.021.
|
| [7] |
A. Banerjee and N. Garofalo, On the space-like analyticity in the extension problem for nonlocal parabolic equations, Proc. Amer. Math. Soc., 151 (2023), 1235-1246.
doi: 10.1090/proc/16220.
|
| [8] |
A. Banerjee and N. Garofalo, Quantitative uniqueness for elliptic equations at the boundary of$C^{1, Dini}$ domains, J. Differential Equations, 261 (2016), 6718-6757.
doi: 10.1016/j.jde.2016.09.001.
|
| [9] |
A. Banerjee and A. Ghosh, Decay at infinity for solutions to some fractional parabolic equations., Proceedings of the Royal Society of Edinburgh: Section A Mathematics, Published online 2024: 1-37.
doi: 10.1017/prm.2024.9.
|
| [10] |
A. Banerjee and S. Senapati, The Calderón problem for space-time fractional parabolic operators with variable coefficients, SIAM J. Math. Anal., 56 (2024), 4759-4810.
doi: 10.1137/23M1584137.
|
| [11] |
A. Banerjee and S. Senapati, Extension problem for the fractional parabolic Lamé operator and unique continuation, Calc. Var. Partial Differential Equations, 63 (2024), Paper No. 203.
doi: 10.1007/s00526-024-02807-4.
|
| [12] |
K. Bellova and F.-H. Lin, Nodal sets of Steklov eigenfunctions, Calc. Var. Partial Differential Equations, 54 (2015), 2239-2268.
doi: 10.1007/s00526-015-0864-8.
|
| [13] |
J. Bourgain and C. E. Kenig, On localization in the continuous Anderson-Bernoulli model in higher dimension, Invent. Math., 161 (2005), 389-426.
doi: 10.1007/s00222-004-0435-7.
|
| [14] |
L. Caffarelli and L. Silvestre, An extension problem related to the fractional Laplacian, Comm. Partial Differential Equations, 32 (2007), 1245-1260.
doi: 10.1080/03605300600987306.
|
| [15] |
G. Camliyurt and I. Kukavica, Quantitative unique continuation for a parabolic equation, Indiana Univ. Math. J., 67 (2018), 657-678.
doi: 10.1512/iumj.2018.67.7283.
|
| [16] |
A. De Luca, V. Felli and G. Siclari, Strong unique continuation from the boundary for thespectral fractional Laplacian, ESAIM Control Optim. Calc. Var., 29 (2023), Paper No. 50, 37 pp.
doi: 10.1051/cocv/2023045.
|
| [17] |
A. De Luca, V. Felli and S. Vita, Strong unique continuation and local asymptotics at theboundary for fractional elliptic equations, Adv. Math., 400 (2022), Paper No. 108279, 67 pp.
doi: 10.1016/j.aim.2022.108279.
|
| [18] |
H. Donnelly and C. Fefferman, Nodal sets of eigenfunctions on Riemannian manifolds, Invent. Math., 93 (1988), 161-183.
doi: 10.1007/BF01393691.
|
| [19] |
H. Donnelly and C. Fefferman, Nodal sets of eigenfunctions: Riemannian manifolds with boundary, Analysis, et Cetera, Academic Press, Boston, MA, (1990), 251-262.
|
| [20] |
L. Escauriaza and F. J. Fernández, Unique continuation for parabolic operators, Ark. Mat., 41 (2003), 35-60.
doi: 10.1007/BF02384566.
|
| [21] |
L. Escauriaza, F. J. Fernández and S. Vessella, Doubling properties of caloric functions, Appl. Anal., 85 (2006), 205-223.
doi: 10.1080/00036810500277082.
|
| [22] |
L. Escauriaza and S. Vessella, Optimal three cylinder inequalities for solutions to parabolic equations with Lipschitz leading coefficients, Inverse Problems: Theory and Applications, Cortona/Pisa, 2002, in: Contemp. Math., vol. 333, Amer. Math. Soc., Providence, RI, 2003, 79-87.
doi: 10.1090/conm/333/05955.
|
| [23] |
M. M. Fall and V. Felli, Unique continuation property and local asymptotics of solutions to fractional elliptic equations, Comm. Partial Differential Equations, 39 (2014), 354-397.
doi: 10.1080/03605302.2013.825918.
|
| [24] |
V. Felli, A. Primo and G. Siclari, On fractional parabolic equations with hardy-type potentials, Commun. Contemp. Math., (2023), Article number 2350062, 1-50.
doi: 10.1142/S0219199723500621.
|
| [25] |
N. Garofalo and F.-H. Lin, Monotonicity properties of variational integrals, $A_p$ weights and unique continuation, Indiana Univ. Math. J., 35 (1986), 245-268.
doi: 10.1512/iumj.1986.35.35015.
|
| [26] |
N. Garofalo and F.-H. Lin, Unique continuation for elliptic operators: A geometric-variational approach, Comm. Pure Appl. Math., 40 (1987), 347-366.
doi: 10.1002/cpa.3160400305.
|
| [27] |
T. Ghosh, M. Salo and G. Uhlmann, The Calderón problem for the fractional Schrödinger equation, Anal. PDE, 13 (2020), 455-475.
doi: 10.2140/apde.2020.13.455.
|
| [28] |
B. F. Jones, Lipschitz spaces and the heat equation, J. Math. Mech., 18 (1968/69), 379-409.
doi: 10.1512/iumj.1969.18.18030.
|
| [29] |
B. F. Jones, A fundamental solution for the heat equation which is supported in a strip, J. Math. Anal. Appl., 60 (1977), 314-324.
doi: 10.1016/0022-247X(77)90021-X.
|
| [30] |
I. Kukavica, Quantitative uniqueness for second order elliptic operators, Duke Math. J., 91 (1998), 225-240.
doi: 10.1215/S0012-7094-98-09111-6.
|
| [31] |
I. Kukavica, Quantitative, uniqueness, and vortex degree estimates for solutions of the Ginzburg-Landau equation, Electron. J. Differential Equations, (2000), No. 61, 15 pp.
|
| [32] |
I. Kukavica and Q. Le, On quantitative uniqueness for parabolic equations, J. Differential Equations, 341 (2022), 438-480.
doi: 10.1016/j.jde.2022.09.011.
|
| [33] |
R.-Y. Lai, Y.-H. Lin and A. Rüland, The Calderón problem for a space-time fractional parabolic equation, SIAM J. Math. Anal., 52 (2020), 2655-2688.
doi: 10.1137/19M1270288.
|
| [34] |
G. M. Lieberman, Second Order Parabolic Differential Equations, , World Scientific Publishing Co., Inc., River Edge, NJ, 1996.
doi: 10.1142/3302.
|
| [35] |
A. Logunov, Nodal sets of Laplace eigenfunctions: Proof of Nadirashvili's conjecture and ofthe lower bound in Yau's conjecture, Ann. of Math., 187 (2018), 241-262.
doi: 10.4007/annals.2018.187.1.5.
|
| [36] |
A. Logunov, Nodal sets of Laplace eigenfunctions: Polynomial upper estimates of the Hausdorff measure, Ann. of Math., 187 (2018), 221-239.
doi: 10.4007/annals.2018.187.1.4.
|
| [37] |
A. Logunov and E. Malinnikova, Nodal sets of Laplace eigenfunctions: Estimates of theHausdorff measure in dimension two and three, 50 years with Hardy spaces, Oper. Theory Adv. Appl., 333-344.
|
| [38] |
V. Z. Meshov, On the possible rate of decrease at infinity of the solutions of second-order partial differential equations, Math. USSR-Sb., 72 (1992), 343-361.
doi: 10.1070/SM1992v072n02ABEH001414.
|
| [39] |
K. Nyström and O. Sande, Extension properties and boundary estimates for a fractional heat operator, Nonlinear Anal., 140 (2016), 29-37.
doi: 10.1016/j.na.2016.02.027.
|
| [40] |
C.-C. Poon, Unique continuation for parabolic equations, Comm. Partial Differential Equations, 21 (1996), 521-539.
doi: 10.1080/03605309608821195.
|
| [41] |
A. Rüland, On Some Rigidity Properties in PDEs, , Dissertation, Rheinischen Friedrich-Wilhelms-Universität Bonn, 2013.
|
| [42] |
A. Rüland, On quantitative unique continuation properties of fractional Schrödinger equations: Doubling, vanishing order and nodal domain estimates, Trans. Amer. Math. Soc., 369 (2017), 2311-2362.
doi: 10.1090/tran/6758.
|
| [43] |
A. Rüland, Unique continuation for fractional Schrödinger equations with rough potentials, Comm. Partial Differential Equations, 40 (2015), 77-114.
doi: 10.1080/03605302.2014.905594.
|
| [44] |
A. Rüland and J.-N. Wang, On the fractional Landis conjecture, J. Funct. Anal., 277 (2019), 3236-3270.
doi: 10.1016/j.jfa.2019.05.026.
|
| [45] |
S. G. Samko, Hypersingular Integrals and Their Applications, volume 5 of Analytical Methods and Special Functions, Taylor & Francis Group, London, 2002.
|
| [46] |
P. R. Stinga and J. L. Torrea, Regularity theory and extension problem for fractional nonlocal parabolic equations and the master equation, SIAM J. Math. Anal., 49 (2017), 3893-3924.
doi: 10.1137/16M1104317.
|
| [47] |
S. Vessella, Carleman estimates, optimal three cylinder inequality, and unique continuation properties for solutions to parabolic equations, Comm. Partial Differential Equations, 28 (2003), 637-676.
doi: 10.1081/PDE-120020491.
|
| [48] |
S. T. Yau, Seminar on Differential Geometry, 102, Princeton University Press, 1982.
|
| [49] |
H. Yu, Unique continuation for fractional orders of elliptic equations, Ann. PDE., 3 (2017), Paper No. 16, 21 pp.
doi: 10.1007/s40818-017-0033-9.
|
| [50] |
J. Zhu, Quantitative uniqueness for elliptic equations, Amer. J. Math., 138 (2016), 733-762.
doi: 10.1353/ajm.2016.0027.
|
| [51] |
J. Zhu, Quantitative uniqueness of solutions to parabolic equations, J. Funct. Anal., 275 (2018), 2373-2403.
doi: 10.1016/j.jfa.2018.07.011.
|
| [52] |
J. Zhu, Doubling property and vanishing order of Steklov eigenfunctions, Comm. Partial Differential Equations, 40 (2015), 1498-1520.
doi: 10.1080/03605302.2015.1025980.
|