Abstract
We derive a classification of the self-adjoint extensions of the three-dimensional Dirac-Coulomb operator in the critical regime of the Coulomb coupling. Our approach is solely based upon the Kreĭn-Višik-Birman extension scheme, or also on Grubb’s universal classification theory, as opposite to previous works within the standard von Neumann framework. This let the boundary condition of self-adjointness emerge, neatly and intrinsically, as a multiplicative constraint between regular and singular part of the functions in the domain of the extension, the multiplicative constant giving also immediate information on the invertibility property and on the resolvent and spectral gap of the extension.
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Notes
In fact, with a slightly more elaborate argument we can better estimate the reminder in (2.13) as a \(O(r^{1-B})\) term; however, this is not needed in the analysis that follows.
References
Abramowitz, M., Stegun, I.A.: Handbook of mathematical functions with formulas, graphs, and mathematical tables, vol. 55 of National Bureau of Standards Applied Mathematics Series, For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, DC (1964)
Alonso, A., Simon, B.: The Birman-Kreĭn-Vishik theory of selfadjoint extensions of semibounded operators. J. Operator Theory 4, 251–270 (1980)
Arai, M.: On essential selfadjointness, distinguished selfadjoint extension and essential spectrum of Dirac operators with matrix valued potentials. Publ. Res. Inst. Math. Sci. 19, 33–57 (1983)
Arai, M., Yamada, O.: Essential selfadjointness and invariance of the essential spectrum for Dirac operators. Publ. Res. Inst. Math. Sci. 18, 973–985 (1982)
Arrizabalaga, N.: Distinguished self-adjoint extensions of Dirac operators via Hardy-Dirac inequalities. J. Math. Phys. 52, 092301 (2011). 14
Arrizabalaga, N., Duoandikoetxea, J., Vega, L.: Self-adjoint extensions of Dirac operators with Coulomb type singularity. J. Math. Phys. 54, 041504 (2013). 20
Berthier, A., Georgescu, V.: On the point spectrum of Dirac operators. J. Funct. Anal. 71, 309–338 (1987)
Bruneau, L., Dereziński, J., Georgescu, V.: Homogeneous Schrödinger operators on half-line. Ann. Henri Poincaré 12, 547–590 (2011)
Burnap, C., Brysk, H., Zweifel, P.F.: Dirac Hamiltonian for strong Coulomb fields. Il Nuovo Cimento B (1971-1996) 64, 407–419 (1981)
Chernoff, P.R.: Schrödinger and Dirac operators with singular potentials and hyperbolic equations. Pac. J. Math. 72, 361–382 (1977)
Esteban, M.J., Lewin, M., Séré, E.: Domains for Dirac-Coulomb min–max levels (2017). arXiv:1702.04976
Esteban, M.J., Loss, M.: Self-adjointness for Dirac operators via Hardy-Dirac inequalities. J. Math. Phys. 48, 112107 (2007). 8
Evans, W.D.: On the unique self-adjoint extension of the Dirac operator and the existence of the Green matrix. Proc. Lond. Math. Soc. (3) 20, 537–557 (1970)
Fall, M.M., Felli, V.: Sharp essential self-adjointness of relativistic Schrödinger operators with a singular potential. J. Funct. Anal. 267, 1851–1877 (2014)
Gallone, M.: Self-adjoint extensions of Dirac operator with Coulomb potential. In: Dell’Antonio, G., Michelangeli, A. (eds.) Advances in Quantum Mechanics, INdAM-Springer series, vol. 18, pp. 169–185. Springer, Berlin (2017)
Gallone, M., Michelangeli, A., Ottolini, A.: Kreĭn-Višik-Birman self-adjoint extension theory revisited, SISSA preprint 25/2017/MATE (2017)
Georgescu, V., Măntoiu, M.: On the spectral theory of singular Dirac type Hamiltonians. J. Operator Theory 46, 289–321 (2001)
Grubb, G.: A characterization of the non-local boundary value problems associated with an elliptic operator. Ann. Scuola Norm. Sup. Pisa (3) 22, 425–513 (1968)
Grubb, G.: Distributions and Operators. Graduate Texts in Mathematics, vol. 252. Springer, New York (2009)
Gustafson, K.E., Rejto, P.A.: Some essentially self-adjoint Dirac operators with spherically symmetric potentials. Israel J. Math. 14, 63–75 (1973)
Hogreve, H.: The overcritical Dirac–Coulomb operator. J. Phys. A 46, 025301 (2013). 22
Kalf, H., Schmincke, U.-W., Walter, J., Wüst, R.: On the Spectral Theory of Schrödinger and Dirac Operators with Strongly Singular Potentials. Lecture Notes in Mathematics, vol. 448, pp. 182–226. Springer, Berlin (1975)
Kato, T.: Holomorphic families of Dirac operators. Math. Z. 183, 399–406 (1983)
Klaus, M., Wüst, R.: Characterization and uniqueness of distinguished selfadjoint extensions of Dirac operators. Comm. Math. Phys. 64, 171–176 (1978/79)
Landgren, J.J., Rejto, P.A.: An application of the maximum principle to the study of essential selfadjointness of Dirac operators. I. J. Math. Phys. 20, 2204–2211 (1979)
Landgren, J.J., Rejto, P.A.: On a theorem of Jörgens and Chernoff concerning essential selfadjointness of Dirac operators. J. Reine Angew. Math. 322, 1–14 (1981)
Landgren, J.J., Rejto, P.A., Klaus, M.: An application of the maximum principle to the study of essential selfadjointness of Dirac operators II. J. Math. Phys. 21, 1210–1217 (1980)
Le Yaouanc, A., Oliver, L., Raynal, J.-C.: The Hamiltonian \((p^2+m^2)^{1/2}-\alpha /r\) near the critical value \(\alpha _c=2/\pi \). J. Math. Phys. 38, 3997–4012 (1997)
Nenciu, G.: Self-adjointness and invariance of the essential spectrum for Dirac operators defined as quadratic forms. Commun. Math. Phys. 48, 235–247 (1976)
Reed, M., Simon, B.: Methods of Modern Mathematical Physics. II. Fourier Analysis, Self-Adjointness. Academic Press [Harcourt Brace Jovanovich, Publishers], New York-London (1975)
Rejto, P.A.: Some essentially self-adjoint one-electron Dirac operators. (With appendix.). Israel J. Math. 9, 144–171 (1971)
Schmincke, U.-W.: Distinguished selfadjoint extensions of Dirac operators. Math. Z. 129, 335–349 (1972)
Schmincke, U.-W.: Essential selfadjointness of Dirac operators with a strongly singular potential. Math. Z. 126, 71–81 (1972)
Thaller, B.: The Dirac Equation, Texts and Monographs in Physics. Springer, Berlin (1992)
Voronov, B.L., Gitman, D.M., Tyutin, I.V.: The Dirac Hamiltonian with a superstrong Coulomb field. Teoret. Mat. Fiz. 150, 41–84 (2007)
Wasow, W.: Asymptotic Expansions for Ordinary Differential Equations. Dover Publications Inc, New York (1987). (Reprint of the 1976 edition)
Weidmann, J.: Oszillationsmethoden für Systeme gewöhnlicher Differentialgleichungen. Math. Z. 119, 349–373 (1971)
Weidmann, J.: Spectral Theory of Ordinary Differential Operators. Lecture Notes in Mathematics. Springer, Berlin (1987)
Wüst, R.: Distinguished self-adjoint extensions of Dirac operators constructed by means of cut-off potentials. Math. Z. 141, 93–98 (1975)
Wüst, R.: Dirac operations with strongly singular potentials. Distinguished self-adjoint extensions constructed with a spectral gap theorem and cut-off potentials. Math. Z. 152, 259–271 (1977)
Xia, J.: On the contribution of the Coulomb singularity of arbitrary charge to the Dirac Hamiltonian. Trans. Am. Math. Soc. 351, 1989–2023 (1999)
Acknowledgements
We are indebted to Naiara Arrizabalaga, Gianfausto Dell’Antonio, Marko Erceg, Diego Noja, and Giulio Ruzza for many instructive and inspirational discussions on the subject of this work.
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This work was partially supported by the 2014-2017 MIUR-FIR grant “Cond-Math: Condensed Matter and Mathematical Physics” code RBFR13WAET.
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Gallone, M., Michelangeli, A. Self-adjoint realisations of the Dirac-Coulomb Hamiltonian for heavy nuclei. Anal.Math.Phys. 9, 585–616 (2019). https://doi.org/10.1007/s13324-018-0219-7
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DOI: https://doi.org/10.1007/s13324-018-0219-7
Keywords
- Dirac-Coulomb operator
- Self-adjoint extensions
- Kreĭn-Višik-Birman extension theory
- Grubb’s universal classification