Chiralp±ipsuperfluid on a sphere

We consider a spinless fermionic $p\ifmmode\pm\else\textpm\fi{}ip$ superfluid living on a two-dimensional sphere. Using superfluid hydrodynamics, we show that the ground state necessarily exhibits topological defects: either a pair of elementary vortices or a domain wall between $p\ifmmode\pm\else\textpm\fi{}ip$ phases. In the topologically nontrivial BCS phase we identify the chiral fermion modes localized on the topological defects and compute their low-energy spectrum.