Factoring in gravitomagnetism could do away with dark matter
Models of galactic rotation curves built of a general relativistic framework could use gravitomagnetism to explain the effects of dark matter
2021-03-04
(Press-News.org) Observations of galactic rotation curves give one of the strongest lines of evidence pointing towards the existence of dark matter, a non-baryonic form of matter that makes up an estimated 85% of the matter in the observable Universe. Current assessments of galactic rotation curves are based upon a framework of Newtonian accounts of gravity, a new paper published in EPJ C, by Gerson Otto Ludwig, National Institute for Space Research, Brazil, suggests that if this is substituted with a general relativity-based model, the need to recourse to dark matter is relieved, replaced by the effects of gravitomagnetism.
The main role of dark matter, Ludwig points out in the paper, has historically been to resolve the disparity between astrophysical observations and current theories of gravity. Put simply, if baryonic matter?--?the form of matter we see around us every day which is made up of protons, neutrons and electrons?--?is the only form of matter, then there shouldn't be enough gravitational force to prevent galaxies from flying apart.
By disregarding general relativistic corrections to Newtonian gravity arising from mass currents, and by neglecting these mass currents, Ludwig asserts these models also miss significant modifications to rotational curves?--?the orbital speeds of visible stars and gas plotted against their radial distance from their galaxy's centre. This is because of an effect in general relativity not present in Newton's theory of gravity?--?frame-dragging or the Lense Thirring effect. This effect arises when a massive rotating object like a star or black hole 'drags' the very fabric of spacetime along with it, in turn giving rise to a gravitomagnetic field.
In this paper, Ludwig presents a new model for the rotational curves of galaxies which is in agreement with previous efforts involving general relativity. The researcher demonstrates that even though the effects of gravitomagnetic fields are weak, factoring them into models alleviates the difference between theories of gravity and observed rotational curves?--?eliminating the need for dark matter. The theory still needs some development before it is widely accepted, with the author particularly pointing out that the time evolution of galaxies modelled with this framework is a complex problem that will require much deeper analysis.
Ludwig concludes by suggesting that all calculations performed with thin galactic disk models performed up until this point may have to be recalculated, and the very concept of dark matter itself, questioned.
INFORMATION:
References
G. O. Ludwig (2021), Galactic Rotation Curve and Dark Matter According to Gravitomagnetism, European Physical Journal C 81:186, DOI 10.1140/epjc/s10052-021-08967-3
ELSE PRESS RELEASES FROM THIS DATE:
2021-03-04
The drug nusinersen is approved for the treatment of 5q spinal muscular atrophy (SMA). The German Institute for Quality and Efficiency in Health Care (IQWiG) has now examined in an early benefit assessment whether the drug offers an added benefit for patients in comparison with the appropriate comparator therapy.
According to the findings, there is an indication of a major added benefit in comparison with best supportive care (BSC) in children with early onset of disease (in the first six months of life). The drug manufacturer did not submit any relevant data for children with a later onset of disease, so that an added benefit in comparison with BSC is not proven here. For infants who are not yet symptomatic but are expected to have early onset ...
2021-03-04
In recent years, researchers have begun using functional magnetic resonance imaging (fMRI) not just for better understanding the neural bases of psychiatric illness, but also for experimental treatment of depression, ADHD, anxiety, PTSD, substance use disorder, and schizophrenia with a technique called real-time fMRI neurofeedback.
While rtfMRI-NF has emerged in recent years as a promising experimental intervention, it's also a costly procedure that requires extensive technical setup to allow for real-time analysis. That's why a quantitative data review was overdue.
A team of END ...
2021-03-04
Texas A&M University researchers have recently shown superior performance of a new oxide dispersion strengthened (ODS) alloy they developed for use in both fission and fusion reactors.
Dr. Lin Shao, professor in the Department of Nuclear Engineering, worked alongside research scientists at the Los Alamos National Laboratory and Hokkaido University to create the next generation of high-performance ODS alloys, and so far they are some of the strongest and best-developed metals in the field.
ODS alloys consist of a combination of metals interspersed with small, nanometer-sized oxide particles and are known for their high creep resistance. This means that as temperatures rise, the materials keep ...
2021-03-04
Researchers at Baylor College of Medicine show that analysis of the proteomics, or all the protein data, from aggressive human cancers is a useful approach to identify potential novel therapeutic targets. They report in the journal Oncogene, the identification of "proteomic signatures" that are associated with clinical measures of aggressive disease for each of the seven cancer types studied. Some signatures were shared between different types of cancer and included cellular pathways of altered metabolism. Importantly, experimental results provided proof-of-concept that their proteomics analysis approach is a valuable strategy to identify potential therapeutic targets.
"There are two notable aspects of this study. One is that ...
2021-03-04
If you dunk a tea bag repeatedly into your mug or open a cream-filled cookie to lick the filling, you might find coping with pandemic isolation a bit easier than others.
A UC Riverside-led study has found people who adopt unique rituals to make everyday tasks more meaningful might feel less lonely.
"We found that something as simple as preparing tea in a certain way, as long as it's interpreted as a ritual, can make the experience more meaningful," said Thomas Kramer, a professor of marketing at UC Riverside's School of Business. "This makes people feel less lonely."
The paper, published ...
2021-03-04
Parkinson's disease has always been considered a brain disorder. However, new research reveals a close link between the disease and certain immune cells in the blood.
Researchers from Aarhus University have taken the first step on a path which can lead to new ways of understanding and, in the long term, possibly treating this widespread disease that affects not only motor functions but also cognition and emotions.
"We know that Parkinson's disease is characterized by an inflammation in the brain, and that this is crucial for the progression of the disease. But in the study, our interest has been focused on the immune cells found outside the brain," explains Marina Romero-Ramos, who is associate professor at the Department of Biomedicine at Aarhus University.
The researchers ...
2021-03-04
COVID-19 pandemic has increased loneliness and other social issues, especially for women, Mayo research finds
ROCHESTER, Minnesota -- Social distancing guidelines have reduced the spread of COVID-19, but lockdowns and isolation also have created or aggravated other well-being concerns, reports new research. Mayo Clinic investigators found a significant increase in loneliness and a decrease in feelings of friendship during the pandemic. The study, published Feb. 20 in the journal Social Science & Medicine, also showed disproportionate negative effects among women and those with poorer health.
The researchers say that while physical distance is important during the pandemic, distance within and among relationships can cause undue harm to a person's mental health and well-being. ...
2021-03-04
Astronomers using the recently installed instrument MAROON-X on Gemini North have determined the mass of a transiting exoplanet orbiting the nearby star Gliese 486. As well as putting the innovative new instrument through its paces, this result, when combined with data from the TESS satellite, precisely measures key properties of a rocky planet that is ideal for follow-up observations with the next generation of ground- and space-based telescopes.
The exoplanet-hunting instrument MAROON-X has obtained its first scientific result from its new home ...
2021-03-04
What The Study Did: This randomized clinical trials reports that among adults with mild COVID-19, a five-day course of ivermectin, compared with placebo, didn't significantly improve the time to resolution of symptoms. The findings don't support the use of ivermectin for treatment of mild COVID-19, although larger trials may be needed to understand the effects of ivermectin on other clinically relevant outcomes.
Authors: Eduardo López-Medina, M.D., M.Sc., of the Centro de Estudios en Infectología Pediátrica in Cali, Colombia, is the corresponding author.
To access the embargoed ...
2021-03-04
What The Article Says: Current best evidence about COVID-19 vaccines, immunity and whether SARS-CoV-2 will become an endemic or seasonal virus is summarized in this Viewpoint.
Authors: Carlos del Rio, M.D., of the Emory University School of Medicine in Atlanta, is the corresponding author.
To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/
(doi:10.1001/jama.2021.3760)
Editor's Note: The article includes conflict of interest disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support.
INFORMATION:
Media advisory: The full article is linked to this news release.
Embed ...
LAST 30 PRESS RELEASES:
[Press-News.org] Factoring in gravitomagnetism could do away with dark matter
Models of galactic rotation curves built of a general relativistic framework could use gravitomagnetism to explain the effects of dark matter
