RT Journal Article T1 On The Irreducible Components Of A Semialgebraic Set A1 Gamboa Mutuberria, José Manuel A1 Fernando Galván, José Francisco AB In this work we define a semialgebraic set S Rn to be irreducible if the noetherian ring of Nash functions on S is an integral domain. Keeping this notion we develop a satisfactory theory of irreducible components of semialgebraic sets, and we use it fruitfully to approach four classical problems in Real Geometry for the ring : Substitution Theorem, Positivstellens¨atze, 17th Hilbert Problem and real Nullstellensatz, whose solution was known just in case S = M is an affine Nash manifold. In fact, wegive full characterizations of the families of semialgebraic sets for which these classical results are true. PB World Scientific Publ SN 0129-167X YR 2012 FD 2012 LK https://hdl.handle.net/20.500.14352/42179 UL https://hdl.handle.net/20.500.14352/42179 NO Spanish GEOR[MTM2011-22435]; GAAR Grupos[UCM 910444] DS Docta Complutense RD 4 abr 2025