Phenomenology of Antigravity in N=2, 8 Supergravity

Abstract

Abstract. N = 2, 8 supergravity predicts antigravity (gravivector and graviscalar) fields in the graviton supermultiplet. Data on the binary pulsar PSR 1913+16, tests of the equivalence principle and searches for a fifth force yield an upper bound of order 1 meter (respectively, 100 meters) on the range of the gravivector (respectively, graviscalar) interaction. Hence these fields are not important in non-relativistic astrophysics (for the weak-field limit of N = 2, 8 supergravity) but can play a role near black holes and for primordial structures in the early universe of a size comparable to their Compton wavelengths.The quest for a unified description of elementary particle and gravity theories led to local supersymmetry [1]. The large symmetry content of supergravity yields, in spite of its lack of renormalizability, powerful constraints on physical observables, e.g. anomalous magnetic moments [2].It has been shown that a clear case for antigravity theories arises, when considering N > 1 supergravity theories [3, 4]. Combining laboratory data together with geophysical and astronomical observations has provided us restrictions on the antigravity features of some extended supergravity theories [5,6]. This can have important consequences for high precision experiments measuring the difference in the gravitational acceleration of the proton and the antiproton [7]. A review of earlier ideas about antigravity is found in [8].The N = 2, 8 supergravity multiplets contain, in addition to the graviton, a vector field A l µ [9], [10,11]. This field, which we refer to as the gravivector, carries antigravity, because it couples to quarks and leptons with a positive sign and to antiquark and antileptons with a negative one. The coupling is proportional to the mass of the matter fields and vanishes for self-conjugated particles. The other antigravity field is the scalar σ entering the N = 8 supergravity multiplet [3, 4]. We refer to it as the graviscalar.We are bound, in force of the result of the Eötvös experiment, to take a nonvanishing mass for the field A l µ [3, 4].where the Higgs mechanism has been invoked. The presence of the gravivector in the theory introduces a violation of the equivalence principle on a range of distances of order the Compton wavelength R l . At present, the equivalence principle is verified with a precision |δγ/γ| <