## Abstract

The possibility of mass in the context of scale-invariant, generally covariant theories, is discussed. Scale invariance is considered in the context of a gravitational theory where the action, in the first-order formalism, is of the form S = ∫ L_{1} Φ d^{4}cursive Greek chi + ∫ L_{2}√-g d^{4}cursive Greek chi where Φ is a density built out of degrees of freedom independent of the metric. For global scale invariance, a "dilaton" φ has to be introduced, with nontrivial potentials V(φ) = f_{1}e^{αφ} in L_{1} and U(φ) = f_{2}e^{2αφ} in L_{2}. This leads to nontrivial mass generation and a potential for φ which is interesting for new inflation. Scale invariant mass terms for fermions lead to a possible explanation of the present day accelerated universe and of cosmic coincidences.

Original language | English |
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Pages (from-to) | 1397-1401 |

Number of pages | 5 |

Journal | Modern Physics Letters A |

Volume | 14 |

Issue number | 21 |

DOIs | |

State | Published - 10 Jul 1999 |