symmetric monoidal (∞,1)-category of spectra
A topological field is a topological ring whose underlying ring is in fact a field and such that reciprocation is continuous. This latter condition is the same as demanding that the subspace topology on induced by the embedding coincide with the subspace topology induced by the embedding . More at topological field.
In a topological ring, the closure of is an ideal. It follows that for a topological field , either is a closed point (so that is and therefore completely regular Hausdorff, by standard arguments in the theory of uniform spaces), or is a codiscrete space.
The real numbers form a topological field.
For any prime , the ring of p-adic integers is a topological ring.