Related papers: Effective gravity and OSp(N,4) invariant matter
The equations of motion for matter fields are invariant under the shift of the matter lagrangian by a constant. Such a shift changes the energy momentum tensor of matter by T^a_b --> T^a_b +\rho \delta^a_b. In the conventional approach,…
A nonlocal form of the effective gravitational action could cure the unboundedness of euclidean gravity with Einstein action. On sub-horizon length scales the modified gravitational field equations seem compatible with all present tests of…
The Maxwell extension of the conformal algebra is presented. With the help of gauging the Maxwell-conformal group, a conformally invariant theory of gravity is constructed. In contrast to the conventional conformally invariant actions, our…
We investigate the cosmology of SO(3)-invariant massive gravity with 5 degrees of freedom. In contrast with previous studies, we allow for a non-trivial fiducial metric, which can be justified by invoking, for example, a dilaton-like global…
We review the OSp(1|4)-invariant formulation of N=1, D=4 supergravity and present its noncommutative extension, based on a star-product originating from an abelian twist with deformation parameter \theta. After use of a geometric…
We obtain the complete set of equations of motion for the interacting system of supermembrane and dynamical D=4 N = 1 supergravity by varying its complete superfield action and writing the resulting superfield equations in the special gauge…
We study linearized perturbations of eleven-dimensional $OSp(32|1)$ Chern-Simons supergravity. The action contains a term that changes the value of the cosmological constant, as considered by Horava. It is shown that the spectrum contains a…
A perturbative non-renormalization theorem is presented that applies to general supersymmetric theories, including non-renormalizable theories in which the $\int d^2\theta$ integrand is an arbitrary gauge-invariant function $F(\Phi,W)$ of…
We formulate the on-shell effective field theory (OSEFT) in an arbitrary frame and study its reparametrization invariance (RI), which ensures that it is respectful of Lorentz symmetry. In this formulation the OSEFT Lagrangian looks formally…
We consider the standard model with local scale invariance. The theory shows exact scale invariance of dimensionally regulated action. We show that massless gauge fields, which may be abelian or non-abelian, lead to vanishing contribution…
We present an exact RG (renormalization group) analysis of $O(N)$-invariant scalar field theory about the Gaussian fixed point. We prove a series of statements that taken together show that the non-polynomial eigen-perturbations found in…
We construct a Lagrangian of Weyl spinors and gauge fields, which is invariant under the action of equivalent local transformations on the spinor algebra representations. A model of vacuum with a nontrivial gauge strength-tensor setting a…
We investigate in 4 spacetime dimensions, all the consistent deformations of the lagrangian ${\cal L}_2+{\cal L}_{{3/2}}$, which is the sum of the Pauli-Fierz lagrangian ${\cal L}_2$ for a free massless spin 2 field and the Rarita-Schwinger…
We review the geometric superspace approach to the boundary problem in supergravity, retracing the geometric construction of four-dimensional supergravity Lagrangians in the presence of a non-trivial boundary of spacetime. We first focus on…
It is well known that the covariant coupling of fermionic matter to gravity induces a four-fermion interaction. The presence of this term in a homogenous and isotropic space-time results in a BCS-like Hamiltonian and the formation of a…
We consider a class of modified gravity models where the terms added to the standard Einstein-Hilbert Lagrangian are just a function of the metric only. For linearized perturbations around an isotropic space-time, this class of models is…
We continue developing cosmological models involving nilpotent chiral superfields, which provide a simple unified description of inflation and the current acceleration of the universe in the supergravity context. We describe here a general…
A closed mathematical model of the statistical self-gravitating system of scalar charged particles for conformal invariant scalar interactions is constructed on the basis of relativistic kinetics and gravitation theory. Asymptotic…
We explore the possibility of a consistent cosmology based on the gauge-fixing independent running of the gravitational and cosmological constants ($G$ and $\Lambda$) in the framework of effective quantum gravity. In particular, their…
A new approach for embedding the renormalization group running of Newton's constant and cosmological constant in gravity is proposed. This approach is based on a gravitational Lagrangian that gives rise to a new class of modified gravity…