In the law $v = H_0 d$, what physical quantity does the Hubble Constant ($H_0$) quantify?

Answer

The current rate of expansion of the universe.

Hubble's constant represents the factor of proportionality linking a galaxy’s distance to its observed recessional velocity, thereby defining how fast the universe is currently expanding.

In the law $v = H_0 d$, what physical quantity does the Hubble Constant ($H_0$) quantify?
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