We propose a model describing Einstein gravity coupled to a scalar field with an exponential potential. We show that the weak-field limit of the model has static solutions given by a gravitational potential behaving for large distances as ln r. The Newtonian term GM/r appears only as subleading. Our model can be used to give a phenomenological explanation of the rotation curves of the galaxies ...

The concept of the vacuum in quantum field theory is a subtle one. Vacuum states have a rich and complex set of properties that produce distinctive, though usually exceedingly small, physical effects. Quantum vacuum noise is familiar in optical and electronic devices, but in this paper I wish to consider extending the discussion to systems in which gravitation, or large accelerations, are impor...

Numerical simulations of self-gravitating flows evolve a momentum equation and an energy that account for accelerations gravitational releases due to time-dependent potential. In this work, we implement fully conservative numerical algorithm flows, using source terms, in the astrophysical magnetohydrodynamics framework Athena++. We demonstrate properly evaluated terms are when they equivalent d...

First, this paper broaches the epistemological status of scientific tenets and approaches: phenomenological (descriptive only), well-founded (solid first principles, conducive to deep understanding), provisional (can be falsified if universal and verified if existential), and imaginary (fictitious entities or processes, conducive to empirically unsupported beliefs). The ΛCDM “concordance model”...

The drag-free satellites of LISA will maintain the test masses in geodesic motion over many years with residual accelerations at unprecedented small levels and time delay interferometry (TDI) will keep track of their differential positions at level of picometers. This may allow investigations of fine details of the gravitational field in the Solar System previously inaccessible. In this spirit,...

Testing alternative metric theories of gravity with an accuracy much better than the present level has recently drawn great attention, in particular in relation to the search for a very weak scalar field, a possible remnant of an early inflationary cosmology. The gravitational deflection of electromagnetic waves is controlled by the dimensionless post-Newtonian parameter γ , which takes a value...

There is a need for large-scale, real world, diverse, and context rich vehicle acceleration catalog that can be used to design, analyze, compare various intelligent transportation systems. This paper fulfills three primary objectives. First, it provides such through the Surface Accelerations Reference, which openly available as an interactive analytics tool well open downloadable dataset. The R...