Hi,
Of course it depends on the circuit. But in SC circuits as current decreases you should decrease the capacitor value to maintain the speed. So, the KT/C noise increases.
maybe the author would have talked about the noise to signal ratio....
it would be better if you quote the whole text or mention the book and page number...
It depends, for CMOS op amp, high current for input pair will reduce the noise, oh, what I said is not correct. Increasing current of input pair will increase both thermal noise and Gm, but for thermal noise, its gain is increased by √2, while for signal, the gain is increased by 2. Compare with each other, the noise is reduced. We often talk about input referred noise