Summary
The procedure for constructing all potentials belonging to a givenS-matrix and prescribed eigenvalue is generalized to systems of equations of the type of the Schrödinger equation forS-states. The determination of the spectral function from theS-matrix is found to be essentially more complicated here than in the case of a single equation, and it leads to restrictions on theS-matrix to make the existence of a short range potential possible. If such a potential exists, it is uniquely determined by theS-matrix, the eigenvalues, and as many real, symmetric, positive semi-definite matrices as there are eigenvalues.
Riassunto
Si generalizza a sistemi di equazioni del tipo dell’equazione di Schrödinger per gli statiS il procedimento per la costruzione di tutti i potenziali appartenenti a una matriceS data e degli autovalori assegnati. Si trova che la determinazione della funzione spettrale a partire dalla matriceS è in questo caso intrinsecamente più complicata che non nel caso di una equazione singola e conduce a restrizioni sulla matriceS tali da render possibile l’esistenza di un potenziale di «short-range». Se un tale potenziale esiste, è unicamente determinato dalla matriceS, dagli autovalori, e da tante matrici semidefinite, positive, simmetriche, reali quanti sono gli autovalori.
Similar content being viewed by others
References
V. Bargmann:Phys. Rev.,75, 301 (1949).
V. Bargmann:Rev. Mod. Phys.,21, 488 (1949).
N. Levinson:Kgl. Danske Videnskab Selsab, Mat.-fys. Medd.,25, No. 9 (1949).
R. Jost andW. Kohn:Phys. Rev.,87, 977 (1952).
R. Jost andW. Kohn:Phys. Rev.,88, 382 (1952).
R. Jost andW. Kohn:Kgl. Danske Videnskab Selsab, Mat.-fys. Medd.,27, No. 9 (1953).
N. Levinson:Phys. Rev.,89, 755 (1953).
W. Rarita andJ. Schwinger:Phys. Rev.,59, 436 (1941).
J. M. Blatt andV. F. Weisskopf:Theoretical Nuclear Physics (New York and London, 1952), pp. 94 ff; (8) and (9) are examples of references to this subject.
I. M. Gel’fand andB. M. Levitan:Dokl. Akad. Nauk SSSR, n. Ser.,77, 557 (1951).
I. M. Gel’fand andB. M. Levitan:Izv. Akad. Nauk SSSR,15, 309 (1951).
C. Møller:Kgl. Danske Videnskab Selsab, Mat.-fys. Medd.,22, No. 19, (1946), p. 19.
This is the proper generalization of the first equation in (1.10) of reference (6).
J. Plemelj:Monatsh. f. Math. u. Phys.,19, 211 (1908).
E. C. Titchmarsh:Theory of Fourier Integrals (Oxford, 1937), pp. 119 ff. The extension to vector and matrix valued function is trivial.
N. I. Muskelishvili:Singular Integral Equations (Groningen, Holland, 1953), pp. 381 ff.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Newton, R.G., Jost, R. The construction of potentials from theS-matrix for systems of differential equations. Nuovo Cim 1, 590–622 (1955). https://doi.org/10.1007/BF02855219
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1007/BF02855219