Thunderbolts of the Gods!

Looking Back to the Future

“At the beginning of the 1900s, it was thought an improved understanding of electromagnetism offered the best way forward for astronomy. It is unfortunate, therefore, that many have become frustrated at the pace of progress in the space sciences. 

Although most sciences have progressed leaps and bounds over the past hundred years, cosmology has fallen behind. Certainly, numerous space missions have enjoyed remarkable success, but is it a testament to the engineers and technicians—or—those theoreticians who are continually surprised by findings that almost always contradict expectations? 

Since July 2022, the James Webb Space Telescope has ramped up the cognitive dissonance as the spiraling, filamentary structure of the universe is being observed more clearly than ever—from an electrical plasma perspective. 

Author and independent researcher David Drew does not claim the EU Model has all the answers, but advocates it will help direct us Back to the Future and herald the next era of cosmology.”

Internal r-process abundance spread of M15 and a single stellar population model. (arXiv:2110.02970v1 [astro-ph.GA])

The member stars in globular cluster M15 show a substantial spread in the abundances of r-process elements. We argue that a rare and prolific r-process event enriched the natal cloud of M15 in an inhomogeneous manner. To critically examine the possibility, we perform cosmological galaxy formation simulations and study the physical conditions for the inhomogeneous enrichment. We explore a large parameter space of the merger event time and the site. Our simulations reproduce the large r-process abundance spread if a neutron-star merger occurs at \sim 100 pc away from the formation site of the cluster and in a limited time range of a few tens million years before the formation. Interestingly, a bimodal feature is found in the Eu abundance distribution in some cases, similarly to that inferred from recent observations. M15 member stars do not show clear correlation between the abundances of Eu and light elements such as Na that is expected in models with two stellar populations. We thus argue that a majority of the stars in M15 are formed in a single burst. Considering the abundances of the first peak r-process elements such as Y and Zr, we conclude that the main r-process event should have a high lanthanide fraction of [Eu/Y] \sim 1.0, consistent with the so-called r-II stars in the Milky Way and Reticulum II.

from astro-ph.HE updates on arXiv.org https://ift.tt/2ZX2Ez8

STFC Fully-Funded Scholarship in Centre for Doctoral Training in Data Intensive Science at Swansea University

Closing date: Position is open until filled. Applications will be assessed on a rolling basis

Start date: 1 October 2020

Swansea University’s Department of Physics has an opening for an STFC/College of Science funded scholarship in 2020 in Particle Physics and Cosmology Theory. The successful applicant will join the 2020 cohort of the Data Intensive Centre for Doctoral Training, a three-university consortium formed by cognate research groups at the universities of Bristol, Cardiff and Swansea. As well as receiving courses delivered at Swansea in theoretical physics, CDT students will benefit from specialist training in data science, and undertake a six-month placement at a commercial or industrial partner organisation.

See https://data-intensive-cdt.ac.uk for further information

Research can be done in several areas of interest within the Particle Physics and Cosmology Theory group at Swansea including:

·         Theoretical cosmology and gravitational waves

·         Hot and dense QCD on the lattice

·         Physics beyond the standard model

·         Quantum Field Theories of Condensed Matter

Applications should be submitted as soon as possible and will be reviewed on a rolling basis. Shortlisted candidates will be invited to interview over Skype or Zoom.

Requirements:

Candidates must have a first, upper second class honours or a Masters degree with Merit, in a relevant discipline. Informal enquiries and queries on eligibility for this programme may be directed to the Swansea CDT lead Prof. Simon Hands [email protected]

Studentships funded by STFC are subject to UK/EU residency eligibility.

For candidates whose first language is not English, we require IELTS 6.5 (with 6.0 in each component) or equivalent. Please visit our website for a list of acceptable English language tests. We prefer candidates to have already met the English Language requirements at the point of application, although this is not a requirement.

Funding:

These are 48 month fully-funded STFC scholarships, which cover UK/EU tuition fees and an annual stipend. The current stipend is £15,285 per annum.

How to apply:

To apply for this studentship, please download the research scholarship application form and Equality, Diversity and Inclusion Form and return them to the College of Science with the following:

·         Academic References – all scholarship applications require two supporting references to be submitted. Please ensure that your chosen referees are aware of the funding deadline, as their references form a vital part of the evaluation process. Please either include these with your scholarship application or ask your referees to send them directly to [email protected]

·         Academic Transcripts and Degree Certificates – academic transcripts and degree certificates must be submitted along with the scholarship application by the funding deadline. We will be using these to verify your academic qualifications.

·         A recent CV

·         Applicants should use the ‘Supplementary Personal Statement’ section of the application form to indicate, in broad terms, their proposed research interests within the activities of the Particle Physics and Cosmology Theory group.

·         Should you wish to also apply for other current scholarship advertisements within the PPCT group please state this directly on your form.

Please email the documents to [email protected] and include ‘STFC 20-21 CDT SCHOLARSHIP APPLICATION’ in the subject line of your application.

Wings of a Butterfly

“In the EU Model of Cosmology, plasma phenomena discharges come in three levels of intensity—dark mode, glow mode, and arc mode. 

In beautiful and intricate structures such as the Butterfly Nebula, the stars-throwing-off-gas theory is REPLACED by normal Birkeland currents in glow mode where the currents are necking down on a star in the typical funnel, hourglass or butterfly shape. The star in the center is hardly even visible. 

Natural Philosopher Michael Armstrong explains how the Standard Model of Cosmology—mired in a bog of phantasmagorical constructs—is long overdue for a major overhaul of the Big Bang, singularities, dark matter, dark energy, black holes, and the doubly reified space-time continuum.”

Seeing Circuits in the Cosmos

“We know that an electric current in plasma generates its own magnetic field and can self-constrict the current channel. This is called a Bennett pinch (or Z-pinch) effect—and is able to produce filaments of current that maintain their shape over vast distances. Multiple filaments tend to spiral around each other, forming helical circuits that transmit electrical charge throughout the cosmos. Almost every body in the Universe displays some kind of filamentation. Venus has a tail composed of invisible “stringy things” (NASA's description). Comets have tails composed of visible stringy things or in reality, Ion tails. The neon-light-glow of planetary nebula look like intricate webs of filamentary, braided string. The spiral arms of some galaxies look hairy with threads of material extending out from their galactic center. Now if these filaments are Birkeland currents as the EU Model suggests—and we're only seeing the visible structures—the rest of the circuit will generate the magnetic fields that are consistently being mapped to help us grasp the extent of these cosmic circuits. Yet another reason why the EU Model of Cosmology is a viable alternative to the Standard Model by seeing, and defining, circuits in the big picture of the cosmos. Its predictive success rate alone demands attention.”

s-process enirchment and the origin of barium in ultrafaint dwarf galaxies. (arXiv:2009.10096v1 [astro-ph.GA])

Recent spectroscopic observations of ultrafaint dwarf galaxies (UFDs) revealed that the small, old galaxies contain a substantial amount of neutron-capture elements such as Barium (Ba), Strontium (Sr) and Europium (Eu). We use cosmological simulations to study the production of Ba in UFDs. Ba is produced by both {\it r-} and {\it s-}processes, and one can infer the contribution of the {\it r-}process from the characteristic {\it r-}process abundance pattern, whereas the {\it s-}process contribution remains largely unknown. We show that the current {\it s-}process yield from asymptotic giant branch (AGB) stars is not sufficient to explain the Ba abundances observed in UFDs. Ba production would need to be efficient from the beginning of star formation in the galaxies. The discrepancy of nearly $1$ dex is not reconciled even if we consider {\it s-}process in super-AGB stars. We consider a possible resolution by assuming additional Ba production with short delay time. Considering the diversity of Ba abundances among different UFDs, a rare and prolific source is favoured. Fast-rotating massive stars could be such rare and prolific sources, and they can account for the observed abundance if $\sim 3\times 10^{-10}$ Msun of Ba is produced per 1 Msun formed stars. We also explore another resolution by modifying the stellar initial mass function (IMF) in UFDs, and find a particular IMF model that reproduces the observed level of Ba-enrichment. We argue that future observations that determine or tightly constrain the Eu abundance are crucial to identify the origin of Ba in UFDs.

from astro-ph.HE updates on arXiv.org https://ift.tt/3cyUgbD

Dynamical Wormholes in Higher Dimensions and the Emergent Universe. (arXiv:2008.03562v1 [gr-qc])

Dynamical wormholes in higher dimensions which admit flat emergent universe (EU) model is presented. The EU model is free from initial singularity with other observed features of the universe. The basic assumption of EU model was that the present universe emerged out from a static Einstein universe. EU model originates from a dynamical wormhole, its throat is the seed of Einstein Static universe. A class of cosmological solutions in a higher dimensional flat universe is presented. A new shape function for closed universe is determined. The non-linear equation of state (EoS) corresponds to three types of cosmic fluids. The EoS parameters determine the cosmic fluids. The space-time dimensions determines the rate of change of a particular fluid that varies with the scale factor of a dynamically evolving universe with non-interacting fluids. Considering interaction at time $t > t_0$, among the three types of fluids it is possible to describe the observed universe satisfactorily. In a higher dimensional universe it is found that near the throat null energy condition (NEC) is violated, but away from the throat NEC is found to obey admitting the observed universe for a flat case. Another interesting aspect of the EU model is that it permits late accelerating phase. However, in asymptotic closed or open universe, flat emergent universe can be accommodated with NEC which is obeyed right from the throat to the present epoch. The tension at the throat of the wormhole is estimated which is found to depend on the initial size of the Einstein static universe and dimensions of the universe. It is interesting to note that NEC is not violated to accommodate dynamical wormholes for closed or open universe. Although exotic matter is required at the throat for the flat universe, no exotic matter is required for closed or open universe which encompass the emergent universe.

from gr-qc updates on arXiv.org https://ift.tt/3fQ0Bz3

On Distinguishing Different Models of a Class of Emergent Universe Solutions. (arXiv:1712.01556v1 [gr-qc])

A specific class of singularity free cosmological model has recently been considered in light of different observational data like Observed Hubble Data, BAO data from Luminous Red Galaxy survey by Slowan Digital Sky Survey (SDSS) and CMB data from WMAP. However it is observed that only $12-14$ data points are used to study the viability of the model in late time . In this paper we discuss the viability of all the models belonging to the same class of EU in light of Union Compilation data (SnIa) which consists over a hundred data points, thus getting a more robust test for viability. More importantly it is crucial that we can distinguish between the various models proposed in the class of solution obtained. We discuss here why with present observational data it is difficult to distinguish between all of them. We show that the late time behaviour of the model is typical to any asymptotically de-Sitter model.

from gr-qc updates on arXiv.org http://ift.tt/2AsoP1z