We address the problem of the large initial field values in chaotic inflation and propose a remedy in the framework of the so-called assisted inflation. We demonstrate that a 4-dimensional theory of multiple, scalar fields with initial field values considerably below the Planck scale, can give rise to inflation even though none of the individual scalar fields are capable of driving inflation. T...

We propose a method to calculate the Greens function of a free massive scalar field on the lattice numerically to very high precision. For masses m < 2 (in lattice units) the massive Greens function can be expressed recursively in terms of the massless Greens function and just two additional mass-independent constants. PACS: 12.90.+b

An action for a massless graviton interacting with a massive spin-2 field is proposed. The model is based on coupling the metric tensor to an SP (4) gauge theory spontaneously broken to SL(2, C). The symmetry breaking is achieved by using a Higgs multiplet containing a scalar field and a vector field related by a constraint. We show that in the non-unitary gauge and for the Fierz-Pauli form of ...

We investigate the worldvolume actions of massive IIA D-branes (i.e. D-branes in a massive IIA background) and obtain explicitly in each case a supersymmetric point charge solution of the worldvolume gauge field with an appropriate excitation of the transverse scalar field. Affected by the background, the form of one of the solutions is very unusual. However, we show that the regularized energy...

We derive and solve the full set of scalar perturbation equations for a class of five-dimensional brane–world solutions, with a dilaton scalar field coupled to the bulk cosmological constant and to a 3-brane. The spectrum contains one localized massless scalar mode, to be interpreted as an effective dilaton on the brane, inducing long–range scalar interactions. Two massive scalar modes yield co...

In this paper we examine Casimir effect in the case of tachyonic field, which is connected with particles with negative four-momentum square (m2 < 0). We consider here only the case of the one dimensional, scalar field. In order to describe tachyonic field, we use the absolute synchronization scheme preserving Lorentz invariance. The renormalized vacuum energy is calculated by means of the Abel...

We consider a simplicial minisuperspace model based on a cone over the α4 triangulation of the 3−sphere, in the presence of a massive scalar field, φ, with arbitrary scalar coupling term ηRφ. By restricting all the interior edge lengths and all the boundary edge lengths to be equivalent and the scalar field to be homogenous on the 3−space, we obtain a two dimensional minisuperspace model {si, φ...

The equations of motion for a massive spin2 Rarita-Schwinger field in a finite-range, central, Lorentz scalar potential are developed. It is shown that the resulting density may not be everywhere positive definite.

In this work we compute the vacuum expectation values of the energymomentum tensor and the average value of a massive, charged scalar field in the presence of a magnetic flux cosmic string for both zeroand finitetemperature cases.