Construction and coupling of frames in Hilbert spaces wiht W-metrics (Q2831528)

The authors give some results on frames in Krein spaces and in Hilbert spaces with W-metric.They give the construction of frames from a positive and J-adjoint operator, prove that two frames are similar if and only if their respective analysis operators have the same range and prove that the coupling of two frames is a frame. For related papers on the subject, see: [\textit{J. I. Giribet} et al., J. Math. Anal. Appl. 393, No. 1, 122--137 (2012; Zbl 1253.46033)] and [\textit{K. Esmeral} et al., Banach J. Math. Anal. 9, No. 1, 1--16 (2015; Zbl 1311.42076)].