Fierz-Pauli Mass Term Research Articles

Geometric Lagrangians for massive higher-spin fields

Lagrangians for massive, unconstrained, higher-spin bosons and fermions are proposed. The idea is to modify the geometric, gauge invariant Lagrangians describing the corresponding massless theories by the addition of suitable quadratic polynomials. These polynomials provide generalisations of the Fierz–Pauli mass term containing all possible traces of the basic field. No auxiliary fields are needed.

Chiral gravity as a covariant formulation of massive gravity

We present a covariant nonlinear completion of the Fierz–Pauli (FP) mass term for the graviton. The starting observation is that the FP mass is immediately obtained by expanding the cosmological constant term, i.e. the determinant of the vielbein, around Minkowski space to second order in the vielbein perturbations. Since this is an unstable expansion in the standard case, we consider an extended theory of gravity which describes two vielbeins that give rise to chiral spin-connections (consequently, fermions of a definite chirality only couple to one of the gravitational sectors). As for Einstein gravity with a cosmological constant, a single fine-tuning is needed to recover a Minkowski background; the two sectors then differ only by a constant conformal factor. The spectrum of this theory consists of a massless and a massive graviton, with FP mass term. The theory possesses interesting limits in which only the massive graviton is coupled to matter at the linearized level.

Strong coupling in massive gravity by direct calculation

We consider four-dimensional massive gravity with the Fierz-Pauli mass term. The analysis of the scalar sector has revealed recently that this theory becomes strongly coupled above the energy scale \Lambda = (M_{Pl}^2 m^4)^{1/5} where m is the mass of the graviton. We confirm this scale by explicit calculations of the four-graviton scattering amplitude and of the loop correction to the interaction between conserved sources.

SL(2,C)gravity with a complex vierbein and its noncommutative extension

We show that it is possible to formulate gravity with a complex vierbein based on SL(2,C) gauge invariance. The proposed action is a four-form where the metric is not introduced but results as a function of the complex vierbein. This formulation is based on the first order formalism. The novel feature here is that integration of the spin-connection gauge field gives rise to kinetic terms for a massless graviton, a massive graviton with the Fierz-Pauli mass term, and a scalar field. The resulting theory is equivalent to bigravity. We then show that by extending the gauge group to GL(2,C} the formalism can be easily generalized to apply to a noncommutative space with the star product. We give the deformed action and derive the Seiberg-Witten map for the complex vierbein and gauge fields.

Effective Lagrangian from higher-curvature terms: absence of a vDVZ discontinuity in AdS space

We argue that the van Dam–Veltman–Zakharov discontinuity arising in the M2 → 0 limit of the massive graviton through an explicit Pauli–Fierz mass term could be absent in anti-de Sitter space. This is possible if the graviton can acquire mass spontaneously from the higher-curvature terms and/or the massless limit M2 → 0 is attained faster than the cosmological constant Λ → 0. We discuss the effects of higher-curvature couplings and an explicit cosmological term (Λ) on the stability of such a continuity and of massive excitations.

Gravitational waves and massive tensor particles in thef-g theory of gravity

Starting from the generally covariant version of the Pauli-Fierz mass term, it is stressed that the tensor fields representing spin-2 particles, eigenstates of strong and gravitational interactions, are linear combinations of one massive and one massless state. This implies that any hadronic reaction, in which massive tensor particles are produced, can be regarded, at least in principle, also as an effective source of gravitons which may become very important in the early stages of the universe; conversely, any process in which gravitational radiation of sufficiently high energy is emitted, should be a source of strongly interacting tensor particles which decay into photons and neutrinos. These two effects could be used for producing and detecting gravitational waves.