When styrene is refluxed with aqueous sulfuric acid, two styrene dimers are formed as the major products.

Question:

When styrene is refluxed with aqueous sulfuric acid, two "styrene dimers" are formed as the major products. One of these styrene dimers is 1,3-diphenyl-1-butene; the other is 1-methyl- 3-phenylindan. Suggest a reasonable mechanism for the formation of each of these compounds.