Hypoellipticity on the Heisenberg group-representation-theoretic criteria
Hypoellipticity on the Heisenberg group-representation-theoretic criteria
A representation-theoretic characterization is given for hypoellipticity of homogeneous (with respect to dilations) left-invariant differential operators <italic>P</italic> on the Heisenberg group <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper H Subscript n"> <mml:semantics> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msub> <mml:mi>H</mml:mi> <mml:mi>n</mml:mi> </mml:msub> </mml:mrow> <mml:annotation encoding="application/x-tex">{H_n}</mml:annotation> </mml:semantics> </mml:math> </inline-formula>; it is the precise analogue for <inline-formula content-type="math/mathml"> …