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Biproducts in pointed, non-linear varieties

Determine whether there exists a non-linear variety with a non-zero object X for which the canonical comparison map Y_{X,X}: X + X -> X × X is an isomorphism.

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Background

In additive (linear) categories, finite sums and products coincide (biproducts). The question asks whether a non-linear pointed variety can nevertheless have a nontrivial object whose binary sum and product coincide.

References

We also turned certain questions which we currently are unable to answer into exercises; these are labelled 'ANK' for 'answer not known'. Is there are non-linear variety with a non-zero object X for which yx,x : X + X -> X x X is an isomorphism?

A Homological View of Categorical Algebra (2404.15896 - Peschke et al., 24 Apr 2024) in Exercise 4.2.13 (Biproduct in a pointed variety) - Section 4.2