Black hole uniqueness from a hidden symmetry of Einstein's gravity

A theorem is proven that the only possible exterior solution for a pseudostationary, rotating, electrovacuum black hole with nondegenerate event horizon is the Kerr-Newman solution withM ²-J²/M²-Q²>0. A special role played in the proof of this theorem by the hidden symmetry groupSU(1, 2) of Einstein's equations is established.This essay received the third award from the Gravity Research Foundation for the year 1983 [Ed.].     

Über Ähnlichkeit,Dehnung und Schrumpfung in der hyperbolischen Geometrie

Ohne Zusammenfassung     

Seiten und Diagonalen eines Kreisvierecks in der hyperbolischen Geometrie

Ohne Zusammenfassung     

Determination of the longitudinal and transverse cross section in resonance electroproduction

Using all relevant data we determine σ_L/σ_T for 1.1<W<1.8 GeV, 0.1<Q ²<2.0 (GeV/c)². New results, emerging in the region of the second and third resonance, are mainly due to our recently published very low ε-data. σ_L/σ_T is found to be small but different from zero.     

Massenspektrometrische Untersuchungen an Azoverbindungen. II—Ermittlung thermodynamischer Größen

The Appearance potentials of azo compounds and their characteristic fragments have been measured. Using these values and the calculated values for the heat of formation of the molecules the heats of formation of molecular ions and fragment ions and the ionization potentials of the latter have been determined. From the dissociation energies it has been concluded that the azo compounds decompose via a two-step pathway.     

Ein neuartiges diophantisches Problem

Ohne ZusammenfassungDem jugendlichenGeorg Faber zum 80. Geburtstag am 5. April 1957