Extra-strong uncertainty principles in relation to phase derivative for signals in Euclidean spaces

This paper devotes to studying uncertainty principles of Heisenberg type for signals defined on Rn taking values in a Clifford algebra. For real-para-vector-valued signals possessing all first-order partial derivatives we obtain two uncertainty principles of which both correspond to the strongest form of the Heisenberg type uncertainty principles for the one-dimensional space. The lower-bounds of the new uncertainty principles are in terms of a scalar-valued phase derivative. Through Hardy spaces decomposition we also obtain two forms of uncertainty principles for real-valued signals of finite energy with the first order Sobolev type smoothness.