arXiv subjects

H. L. Helfer

Publications and source records attributed to H. L. Helfer.

4 recordsLinked to original sources

arXiv2020

II. A GR Source Term $T^{μν}$ For Dark Matter

Two forms are suggested for the energy-momentum source term associated with an aggregate of dark matter (with the properties described in Paper I). Both have large pressure-like components which dominate the density terms. Using one form a simple model of the spiral galaxy halos is developed which can match the observed `flat' outer rotation curves of some galaxies,including the Milky Way. It can also represent the ascending outer rotational curves of small spiral galaxies such as M33. See Figs. 1, 2. The halo dark matter (DM)`missing mass' results from ignoring the pressure term's contribution to the source tensor. The analysis of the Milky Way rotation curve gives parameters characterizing the DM intergalactic medium in which the halo is situated.. The dark matter cannot come closer to the galactic center than $R \sim 4$ kpc. It reaches a maximum flux at $R_h \simeq 8$ kpc and then falls rapidly with distance. It is hoped that by analyzing other galactic rotation curves these models can be used to infer properties of the intergalactic DM matter. The other form for $T^{μν}$ for DM is useful in cosmology. Then a (non-constant) cosmological `constant' term $Λ$ needs to be added to Einstein's equation in order to allow use for DM of the standard equation of state relation of ordinary matter.. We suggest that at least some of the `dark energy' present results from this requirement and may not be real; it simply results from adopting an improper equation of state for DM.

gr-qc↗

arXiv2017

A Model For Dark Matter Halos

A dark matter halo model is developed postulating a new state of matter, entities which have internal spin-like terms. Their motion in an external Schwarzschild metric is discussed. The internal spin motion contributes to the centrifugal force along with the usual orbital angular momentum term and can severely limit the distance of closest approach to the attractor. An energy-momentum tensor associated with an aggregate of them is shown to have primarily pressure-like components. A model of the spiral galaxy halos is developed which can match the observed `flat' rotation curves of some galaxies. The halo dark matter `missing mass' results from the pressure term's contribution to the metric tensor. A possible rationale for the presence of the cosmological constant is discussed. An addendum to the standard cosmology picture allows an estimate of the amount of dark matter; this is in reasonable agreement with that observed. It is possible that the adopted representation of the internal spin motion could be replaced by a boson string Lagrangian.

physics.gen-ph↗

arXiv2003

Development of an elementary climate model: two-layer cellular case

A qualitative understanding of the greenhouse effect has long been available through models based on globally- and time-averaged quantities. We examine here a simple 864-cell climatological model that emphasizes vertical radiative energy transport within each cell. It reproduces yearly average temperatures obtained earlier from one of these global models and predicts a locally distributed non-radiative flux when observed temperatures are employed as input data. Vertical and lateral transport of latent heat do not appear explicitly in this model. They are apparently handled well by one non-radiative flux variable, SNR, which shows a strong latitude dependence. Only the Sahara desert and Saudi Arabian regions appear to be complex. For those interested in climatology and construction of climate models, our model provides constraints upon specifying averaged non-radiative energy transport. The model is a useful simplification for learning about radiative energy transfer into and out of Earth?s atmosphere and for representing the results of more sophisticated models.

physics.ao-ph↗

arXiv2003

On the Interpretation Of the Local Dark Matter

The cause of the extended rotation curves of galaxies is investigated. It is shown that conventional sources and most exotic sources for the needed gravitational fields are implausible. We suggest spatial fluctuations in a scalar field, similar to the inflation field, are responsible for the gravitational fields. These fluctuations play the role of `dark' halos around galaxies. They take $\sim 10^5$ yrs to develop and could not have been important in the early days of the universe. When galaxies are clustered, a $Λ-$term appears naturally in this theory. The universe's present energy density associated with these scalar field ariations is $Ω\sim 1/2-2/3$. A possible scenario is uggested in which the cosmic scale factor ${\cal R}(t)$ would have experienced a recent acceleration. A discussion of further observations and theoretical work needed to resolve some ambiguities in the theory is given.

astro-ph↗