Mathematics developed new classes of stellar dynamics systems solutions
2021-02-05
(Press-News.org) The Vlasov-Poisson equations describe many important physical phenomena such as the distribution of gravitating particles in the interstellar space, high-temperature plasma kinetics, and the Landau damping effect. A joint team of scientists from the Mathematical Institute of RUDN University and the Mathematical Institute of the University of Munich suggested a new method to obtain stationary solutions for a system of Vlasov-Poisson equations in a three-dimensional case. The obtained solutions describe the phenomena of stellar dynamics. The results of the study were published in the Doklady Mathematics journal.
Modern-day physics distinguishes between four main types of interactions. Elementary particle physics covers strong and weak interactions, electromagnetism is studied by electrodynamics, and systems with gravitational interaction fall into the scope of a special branch of physics called gravidynamics. On the space scale, gravitational fields play a key role. One domain of study within gravidynamics is called stellar dynamics.
"We have considered a three-dimensional stationary system of the Vlasov-Poisson equations concerning the distribution function of gravitating matter, local density, and Newtonian potential, and developed a new method for obtaining spherically symmetric stationary solutions. This was the result of our fruitful collaboration with renowned German scientists J. Batt and E. Joern," said Alexander Skubachevskii, a D Sc in Physics and Mathematics, and the Head of the Nikolskii Mathematical Institute of RUDN University.
The movement and interaction of multiple particles in gravitational, electric, and electromagnetic fields are described using the equations that were developed by the eminent Soviet physicist Anatoly Vlasov. They model the dynamics and stationary distribution of a system of particles in view of the influence of a self-consistent field. The Vlasov-Poisson equation for a system of gravitating particles consists of the Poisson equation covering the gravitational potential and the Vlasov equation covering the function of density distribution in interconnected particles. Vlasov's model was initially supposed to describe electron gas dynamics. The model views processes in plasma not as a series of collisions between individual particles but as a simplified system in which particles interact through a field, and the field, in turn, correlates with the particle density distribution function. Therefore, the Vlasov equations are sometimes called equations with a self-consistent field. Together with his German colleagues, the mathematician from RUDN University established the theorem of expandability, i.e. demonstrated how the local density function should look like in order for it to be supplemented to a stationary spherically symmetric solution of the Vlasov-Poisson system.
INFORMATION:
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
2021-02-05
Global greenhouse gas emissions over the last century have made southern China a hotspot for bat-borne coronaviruses, by driving growth of forest habitat favoured by bats.
A new study published today in the journal Science of the Total Environment provides the first evidence of a mechanism by which climate change could have played a direct role in the emergence of SARS-CoV-2, the virus that caused the COVID-19 pandemic.
The study has revealed large-scale changes in the type of vegetation in the southern Chinese Yunnan province, and adjacent regions in Myanmar and Laos, over the last century. Climatic changes ...
2021-02-05
Neanderthals' gut microbiota already included some beneficial micro-organisms that are also found in our own intestine. An international research group led by the University of Bologna achieved this result by extracting and analysing ancient DNA from 50,000-year-old faecal sediments sampled at the archaeological site of El Salt, near Alicante (Spain).
Published in Communication Biology, their paper puts forward the hypothesis of the existence of ancestral components of human microbiota that have been living in the human gastrointestinal tract since before the separation between the Homo Sapiens and Neanderthals that occurred more than 700,000 years ago.
"These results allow us to understand which components of the human gut microbiota ...
2021-02-05
New research has identified a nanostructure that improves the anode in lithium-ion batteries
Instead of using graphite for the anode, the researchers turned to silicon: a material that stores more charge but is susceptible to fracturing
The team made the silicon anode by depositing silicon atoms on top of metallic nanoparticles
The resulting nanostructure formed arches, increasing the strength and structural integrity of the anode
Electrochemical tests showed the lithium-ion batteries with the improved silicon anodes had a higher charge capacity and longer lifespan
New research conducted by the Okinawa Institute of Science and Technology ...
2021-02-05
USC researchers have developed a new method to counter emergent mutations of the coronavirus and hasten vaccine development to stop the pathogen responsible for killing thousands of people and ruining the economy.
Using artificial intelligence (AI), the research team at the USC Viterbi School of Engineering developed a method to speed the analysis of vaccines and zero in on the best potential preventive medical therapy.
The method is easily adaptable to analyze potential mutations of the virus, ensuring the best possible vaccines are quickly identified -- solutions that give ...
2021-02-05
The early prognosis of high-risk older adults for amnestic mild cognitive impairment (aMCI), using noninvasive and sensitive neuromarkers, is key for early prevention of Alzheimer's disease. A recent study, published in the Journal of Alzheimer's Disease, by researchers at the University of Kentucky establishes what they believe is a new way to predict the risk years before a clinical diagnosis. Their work shows that direct measures of brain signatures during mental activity are more sensitive and accurate predictors of memory decline than current standard behavioral testing.
"Many studies have measured electrophysiological rhythms during resting and sleep ...
2021-02-05
Scientists at Tokyo Institute of Technology (Tokyo Tech) and NTT Corporation (NTT) develop a novel CMOS-based transceiver for wireless communications at the 300 GHz band, enabling future beyond-5G applications. Their design addresses the challenges of operating CMOS technology at its practical limit and represents the first wideband CMOS phased-array system to operate at such elevated frequencies.
Communication at higher frequencies is a perpetually sought-after goal in electronics because of the greater data rates that would be possible and to take advantage of underutilized ...
2021-02-05
A new study in Frontiers in Marine Science provides a first-of-its-kind evaluation of which regions of southern European seas are in the most need of fishing restrictions. These areas have persistently shown high numbers of undersized fish and crustaceans, which are typically discarded because they are below the allowable size limit for collection. These findings may offer a strategy for prioritizing conservation efforts and ensuring more sustainable fishery management in the future.
"Natural fish populations need time to reproduce and recover from fishing impacts -- this is the only way to achieve a balance between natural resources and human exploitation," says lead author Dr Giacomo Milisenda, of the Stazione Zoologica Anton Dohrn di Napoli in ...
2021-02-05
Multidisciplinary team of international experts suggests participants should receive a "substantial" amount, be paid ethically
Healthy people volunteering to be infected with SARS-CoV-2, in order to help scientists better understand how to tackle the virus, should receive payment - if it is determined that these studies are otherwise ethical to proceed.
Those are the findings of a new peer-reviewed study published in the American Journal of Bioethics, which has assessed the ethics of paying participants to take part in so-called 'Human Infection Challenge Studies' (HICS).
Over ...
2021-02-05
SSRgenotyper is a newly developed, free bioinformatic tool that allows researchers to digitally genotype sequenced populations using simple sequence repeats (SSRs), a task that previously required time-consuming lab-based methods.
Reporting in a recent issue of Applications in Plant Sciences, the tool's developers designed the program to seamlessly integrate with other applications currently used for the detection and analysis of SSRs.
Simple sequence repeats are short chains of repeating nucleotides that are prone to mutation. The variability of these DNA sequences makes them ideal for genetic analyses to distinguish between individuals and are often the marker of choice for paternity and forensic testing.
In research fields, SSRS have ...
2021-02-05
American actor Robin Williams had a neurodegenerative brain disease called dementia with Lewy bodies (DLB): a distressing disease, with symptoms in common with Alzheimer's disease (AD) and Parkinson's disease (PD). But unlike these two conditions, DLB also entails prominent mood and cognitive swings, sleep disorders, and vivid, sometimes terrifying, visual hallucinations. It is now thought that Robin Williams, whose diagnosis was only ascertained post-mortem, was likely driven to suicide, in 2014, by the terrifying hallucinatory experiences he suffered for years - and about which he never told anyone, not even his wife. Susan Schneider Williams recounted the tragic story in an editorial published in the journal ...
LAST 30 PRESS RELEASES:
[Press-News.org] Mathematics developed new classes of stellar dynamics systems solutions
