@article{RoosOtoba2021,
  author    = {Roos, Saskia and Otoba, Nobuhiko},
  title     = {Scalar curvature and the multiconformal class of a direct product Riemannian manifold},
  series = {Geometriae dedicata},
  volume    = {214},
  journal   = {Geometriae dedicata},
  number    = {1},
  publisher = {Springer},
  address   = {Dordrecht},
  issn      = {0046-5755},
  doi       = {10.1007/s10711-021-00636-9},
  pages     = {801 -- 829},
  year      = {2021},
  abstract  = {For a closed, connected direct product Riemannian manifold (M, g) = (M-1, g(1)) x ... x (M-l, g(l)), we define its multiconformal class [[g]] as the totality {integral(2)(1)g(1) circle plus center dot center dot center dot integral(2)(l)g(l)} of all Riemannian metrics obtained from multiplying the metric gi of each factor Mi by a positive function fi on the total space M. A multiconformal class [[ g]] contains not only all warped product type deformations of g but also the whole conformal class [(g) over tilde] of every (g) over tilde is an element of[[ g]]. In this article, we prove that [[g]] contains a metric of positive scalar curvature if and only if the conformal class of some factor (Mi, gi) does, under the technical assumption dim M-i = 2. We also show that, even in the case where every factor (M-i, g(i)) has positive scalar curvature, [[g]] contains a metric of scalar curvature constantly equal to -1 and with arbitrarily large volume, provided l = 2 and dim M = 3.},
  language  = {en}
}