Bueno, PabloFarràs Busquets, Miquel2025-07-232025-07-232025-06https://hdl.handle.net/2445/222520Treballs Finals de Grau de Física, Facultat de Física, Universitat de Barcelona, Curs: 2025, Tutor: Pablo BuenoBuchdahl’s theorem in four dimensions establishes a universal bound on the degree of compactness of a static star of radius R. The bound is saturated by constant-density stars with infinite central pressure and in terms of the stars’ Schwarzschild radius reads R ≥ 9 8 rS. We show that the theorem holds for D-dimensional Einstein gravity and that the limit becomes R ≥ h (D−1)2 4(D−2) i1/(D−3) rS. We show that the bound is modified when Einstein gravity is corrected by a quadratic higher-curvature term of the Gauss-Bonnet type. In that case, the degree of compactness can be significantly reduced with respect to the Einsteinian result.6 p.application/pdfengcc-by-nc-nd (c) Farràs, 2025http://creativecommons.org/licenses/by-nc-nd/3.0/es/Relativitat general (Física)Teorema de BuchdahlTreballs de fi de grauGeneral relativity (Physics)Buchdahl's theoremBachelor's thesesinfo:eu-repo/semantics/bachelorThesisinfo:eu-repo/semantics/openAccess