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5 votes
1 answer
318 views

Irreducible 3-manifold with boundary of genus greater than 1

Let $M$ be an irreducible 3-manifold with incompressible boundary of genus > 1. When is $M$ homotopy equivalent to an Eilenberg-MacLane space? Or it is never true?
GSM's user avatar
  • 223
1 vote
0 answers
137 views

Covers of a 4-manifold pull back a cohomology class to any algebraic multiple

Fix an algebraic integer $x\neq 0$. Is there a closed smooth 4-manifold $M$ with a class $\rho\in H^{1}_{\mathrm {dR} }(M)$ and a smooth covering map $\phi:M\to M$ such that $\phi^*\rho=x\rho$? Is ...
user avatar
2 votes
1 answer
372 views

isotopy classes of embeddings of the torus

Let's consider $S^1$-bundle $E$ over a 2-manifold $M$. How many isotopy classes of embeddings of the torus $\mathbb{T}^2$ in $E$? For each free homotopy classes $\gamma$ of mappings of the circle ...
Gleb's user avatar
  • 251
4 votes
2 answers
472 views

Does a homeomorphism of $S^1 \times S^2$ which is homotopy to the identity has to isotope to it?

I guess the question can be asked for all manifolds. But I am particularly interested in $S^1 \times S^2$ right now. Concrete example preferrd.
Xiaolei Wu's user avatar
  • 1,598