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Optimal regularity for the Signorini problem


We prove under general assumptions that solutions of the thin obstacle or Signorini problem in any space dimension achieve the optimal regularity C 1,1/2. This improves the known optimal regularity results by allowing the thin obstacle to be defined in an arbitrary C 1,β hypersurface, β > 1/2, additionally, our proof covers any linear elliptic operator in divergence form with smooth coefficients. The main ingredients of the proof are a version of Almgren’s monotonicity formula and the optimal regularity of global solutions.

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Correspondence to Nestor Guillen.

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Guillen, N. Optimal regularity for the Signorini problem. Calc. Var. 36, 533 (2009).

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