2021/11/01 by Hillman, Jonathan A.
#57K30 #57P10 #FOS: Mathematics #Geometric Topology (math.GT)
paper · doi:10.48550/arxiv.2111.01284
We show that if P is a PD3-complex and g∈π1(P) has finite order >1 and infinite centraliser then π1(P) retracts onto Z/2Z⊕ℤ. If P is an irreducible closed 3-manifold then it follows from the Projective Plane Theorem that P≅RP2×S1.