Abstract
We investigate the notion of conditionally positive definite in the context of Hilbert \(C^*\)-modules and present a characterization of the conditionally positive definiteness in terms of the usual positive definiteness. We give a Kolmogorov type representation of conditionally positive definite kernels in Hilbert \(C^*\)-modules. As a consequence, we show that a \(C^*\)-metric space (S, d) is \(C^*\)-isometric to a subset of a Hilbert \(C^*\)-module if and only if \(K(s,t)=-d(s,t)^2\) is a conditionally positive definite kernel. We also present a characterization of the order \(K'\le K\) between conditionally positive definite kernels.
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Amyari, M., Chakoshi, M., Moslehian, M.S.: Quasi-representations of Finsler modules over \(C^*\)-algebras. J. Oper. Theory 70(1), 181–190 (2013)
Arambasić, L., Bakić, D., Moslehian, M.S.: A treatment of the Cauchy–Schwarz inequality in \(C^*\)-modules. J. Math. Anal. Appl. 381, 546–556 (2011)
Barreto, S.D., Bhat, B.V.R., Liebscher, V., Skeide, M.: Type I product systems of Hilbert modules. J. Funct. Anal. 212(1), 121–181 (2004)
Berg, C., Christensen, J.P.R., Ressel, P.: Harmonic Analysis on Semigroups: Theory of Positive Definite and Related Functions. Graduate Texts in Mathematics, 100. Springer-Verlag, New York (1984)
Bhatia, R., Sano, T.: Loewner matrices and operator convexity. Math. Ann. 344(3), 703–716 (2009)
Donoghue, W.F.: Monotone matrix functions and analytic continuation, Die Grundlehren der mathematischen Wissenschaften, vol. 207. Springer-Verlag, Berlin (1974)
Evans, D.E., Lewis, J.T.: Dilations of Irreversible Evolutions in Algebraic Quantum Theory. Communications of the Dublin Institute of Advanced Studies – Series A, no. 24, v\(+\)104 pp (1977)
Ferreira, J.C., Menegatto, V.A.: Positive definiteness, reproducing kernel Hilbert spaces and beyond. Ann. Funct. Anal. 4(1), 64–88 (2013)
Frank, M.: Geometrical aspects of Hilbert \(C^*\)-modules. Positivity 3(3), 215–243 (1999)
Lance, E.C.: Hilbert \(C^*\)-Modules. London Math. Soc. Lecture Note Series, vol. 210, Cambridge University Press, Cambridge (1995)
Ma, Z., Jiang, L., Sun, H.: \(C^*\)-algebra-valued metric spaces and related fixed point theorems. Fixed Point Theory Appl. 2014, 11 (2014)
Manuilov, V.M., Troitsky, E.V.: Hilbert \(C^*\)-modules. Translated from the 2001 Russian original by the authors. Trans. Math. Monog. 226. AMS, Providence, RI (2005)
Murphy, G.J.: Positive definite kernels and Hilbert \(C^*\)-modules. Proc. Edinb. Math. Soc. (2) 40(2), 367–374 (1997)
Micchelli, C.A.: Interpolation of scattered data: distance matrices and conditionally positive definite functions. Constr. Approx. 2(1), 11–22 (1986)
Moslehian, M.S., Joita, M., Ji, U.C.: KSGNS type constructions for \(\alpha \)-completely positive maps on Krein \(C^*\)-modules. Complex Anal. Oper. Theory 10(3), 617–638 (2016)
Pellonpää, J.-P.: Modules and extremal completely positive maps. Positivity 18(1), 61–79 (2014)
Schoenberg, I.J.: Metric spaces and positive definite functions. Trans. Am. Math. Soc. 44(3), 522–536 (1938)
Takesaki, M.: Theory of Operator Algebras. I. Reprint of the first (1979) edition. Encyclopaedia of Mathematical Sciences. 124. Operator Algebras and Non-commutative Geometry, 5. Springer-Verlag, Berlin (2002)
Acknowledgements
The author was supported by a grant from Ferdowsi University of Mashhad (No. 2/42346). He would like to thank the referee for several useful comments improving the paper.
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Moslehian, M.S. Conditionally positive definite kernels in Hilbert \(C^*\)-modules. Positivity 21, 1161–1172 (2017). https://doi.org/10.1007/s11117-016-0458-5
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DOI: https://doi.org/10.1007/s11117-016-0458-5
Keywords
- Conditionally positive definite kernel
- Positive definite kernel
- Hilbert \(C^*\)-module
- Kolmogorov respresentation