Wavelet power spectra (left and middle columns) and wavelet cross-power spectra (right column) for oscillations in brightness temperature (top row), horizontal displacement (middle row), and width (bottom row) at two consecutive slits along the fibril. The cross-hatched areas indicate the wavelet’s cone of influence. In the cross-power spectra, arrows represent the phase relationship between oscillations at the two slits: rightward arrows indicate in-phase oscillations (0°), leftward arrows indicate antiphase oscillations (180°), and downward arrows indicate the second slit leading the first by 90°. Black contours in all panels mark the 95% confidence level.