Wandering Vectors and Frame Representations in Quaternionic Hilbert Spaces
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Abstract
We develop the theory of wandering vectors and frame representations in separable right quaternionic Hilbert spaces. We introduce the local commutant and obtain operator-theoretic characterizations of complete wandering vectors and normalized tight frame vectors. We prove that every complete normalized tight frame vector admits a dilation to a complete wandering vector in a larger quaternionic Hilbert space. Finally, we show that every quaternionic frame representation of a discrete group is unitarily equivalent to a subrepresentation of the left regular representation, yielding a canonical model for such representations.
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References
- D. Alpay, H.T. Kaptanoğlu, Quaternionic Hilbert Spaces and a von Neumann Inequality, Complex Var. Elliptic Equ. 57 (2012), 667–675. https://doi.org/10.1080/17476933.2010.534141.
- S.L. Adler, Quaternionic Quantum Mechanics and Quantum Fields, Oxford University Press, New York, 1995. https://doi.org/10.1093/oso/9780195066432.001.0001.
- P.G. Casazza, The Art of Frame Theory, Taiwan. J. Math. 4 (2000), 129–201. https://doi.org/10.11650/twjm/1500407227.
- Q. Chen, P. Dang, T. Qian, A Frame Theory of Hardy Spaces with the Quaternionic and the Clifford Algebra Settings, Adv. Appl. Clifford Algebr. 27 (2017), 1073–1101. https://doi.org/10.1007/s00006-016-0736-0.
- O. Christensen, An Introduction to Frames and Riesz Bases, second ed., Birkhäuser, Cham, 2016. https://doi.org/10.1007/978-3-319-25613-9.
- F. Colombo, I. Sabadini, D.C. Struppa, Noncommutative Functional Calculus: Theory and Applications of Slice Hyperholomorphic Functions, Birkhäuser, Basel, 2011. https://doi.org/10.1007/978-3-0348-0110-2.
- R.J. Duffin, A.C. Schaeffer, A Class of Nonharmonic Fourier Series, Trans. Am. Math. Soc. 72 (1952), 341–366. https://doi.org/10.1090/S0002-9947-1952-0047179-6.
- R. Ghiloni, V. Moretti, A. Perotti, Continuous Slice Functional Calculus in Quaternionic Hilbert Spaces, Rev. Math. Phys. 25 (2013), 1350006. https://doi.org/10.1142/S0129055X13500062.
- X. Dai, D.R. Larson, Wandering Vectors for Unitary Systems and Orthogonal Wavelets, Mem. Am. Math. Soc. 134 (1998), no. 640. https://doi.org/10.1090/memo/0640.
- D. Han, D.R. Larson, Frames, Bases and Group Representations, Mem. Am. Math. Soc. 147 (2000), no. 697. https://doi.org/10.1090/memo/0697.
- C.-K. Ng, On Quaternionic Functional Analysis, Math. Proc. Camb. Philos. Soc. 143 (2007), 391–406. https://doi.org/10.1017/S0305004107000187.
- S.K. Sharma, S. Goel, Frames in Quaternionic Hilbert Spaces, Zh. Mat. Fiz. Anal. Geom. 15 (2019), 395–411. https://doi.org/10.15407/mag15.03.395.