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Black hole low-mass X-ray binary (BH-LMXB) systems are exceptional laboratories for studying accretion physics under strong gravity. The variability of these systems, characterised by the power spectra, changes systematically in different states. We conducted a comprehensive timing analysis of all the AstroSat archival data of 14 BH-LMXB spanning from 2016 to 2024 and found 29 QPOs (quasi-periodic oscillations). The origin of these QPOs remains debated; the most favoured mechanism is Lense-Thirring precession of hot electron corona located in the inner region of the accretion flow, though its precise geometry remains uncertain. We find a clear inclination dependence in time lag behavior between the photons coming from the accretion and the corona, which can be a tracer of the coronal extent. High-inclination sources show lag and RMS transitions, while low-inclination sources mainly exhibit a reversal in the RMS spectral slope, likely due to relativistic effects at smaller radii. These results provide critical insights into coronal structural evolution across BH-LMXB spectral states.
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