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Archive for the ‘mathematics’ category: Page 133

Jun 18, 2019

Study sheds light on gauge invariance in ultrastrong-coupling cavity quantum electrodynamics

Posted by in categories: mathematics, quantum physics

In quantum electrodynamics, the choice of gauge (i.e. specific mathematical formalism used to regulate degrees of freedom) can greatly influence the form of light-matter interactions. Interestingly, however, the “gauge invariance” principle implies that all physical results should be independent from a researcher’s choice of gauge. The quantum Rabi model, which is often used to describe light-matter interactions in cavity-QED, has been found to violate this principle in the presence of ultrastrong light-matter coupling, and past studies have attributed this failure to the finite-level truncation of the matter system.

A team of researchers at RIKEN (Japan), Università di Messina (Italy) and the University of Michigan (U.S.) have recently carried out a study investigating this topic further. In their paper, published in Nature Physics, they identified the source of this gauge violation and provided a method to derive light-matter Hamiltonians in truncated Hilbert spaces, which can produce gauge-invariant physical results even in extreme light-matter interaction regimes.

“Ultrastrong coupling between light and matter has, in the past decade, transitioned from a theoretical idea to an experimental reality,” Salvatore Savasta, one of the researchers who carried out the study, told Phys.org. “It is a new regime of light-matter interaction, which goes beyond weak and strong coupling to make the coupling strength comparable to the transition frequencies in the system. These regimes, besides enabling intriguing new physical effects, as well as many , represents an opportunity to deepen our understanding subtle aspects of the interaction of light and matter.”

Jun 12, 2019

Asteroid mining not a million miles away

Posted by in categories: computing, engineering, mathematics, space travel

Work by a team of University of Adelaide scientists to perfect metal and mineral extraction processes is bringing the possibility of mining the wealth contained within asteroids closer to reality. But science fiction won’t become fact until asteroid mining becomes economically as well as technically viable.

“Asteroids such as Bennu are closer to us than Adelaide is to Alice Springs, about 1000 kilometres away in Earth’s near orbit,” says Professor Volker Hessel, Deputy Dean-Research from the University of Adelaide’s Faculty of Engineering, Computer & Mathematical Sciences (ECMS) and Professor in the School of Chemical Engineering.

“Advances in space exploration mean that these bodies which contain nickel, cobalt, and platinum as well as water and organic matter, are now within reach.”

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Jun 10, 2019

Mathematical Beauty Activates Same Brain Region as Great Art or Music

Posted by in categories: mathematics, media & arts, neuroscience

People who appreciate the beauty of mathematics activate the same part of their brain when they look at aesthetically pleasing formula as others do when appreciating art or music, suggesting that ther.

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Jun 10, 2019

Immortality is mathematically impossible, new research finds

Posted by in categories: biotech/medical, information science, life extension, mathematics

A mathematical equation has proven that controlling one of the two major changes in a cell—decay or cancerous growth—enhances the other, causing inevitable death.

NEXT NEWS ❯

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May 29, 2019

Famous unsolved math problem sees new progress

Posted by in category: mathematics

Mathematicians say an old approach to the Riemann Hypothesis is worth revisiting. Whoever solves it gets at $1 million prize.

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May 28, 2019

Researchers crack an enduring physics enigma

Posted by in categories: mathematics, physics

For decades, physicists, engineers and mathematicians have failed to explain a remarkable phenomenon in fluid mechanics: the natural tendency of turbulence in fluids to move from disordered chaos to perfectly parallel patterns of oblique turbulent bands. This transition from a state of chaotic turbulence to a highly structured pattern was observed by many scientists, but never understood.

At EPFL’s Emerging Complexity in Physical Systems Laboratory, Tobias Schneider and his team have identified the mechanism that explains this phenomenon. Their findings have been published in Nature Communications.

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May 24, 2019

Closer To Truth

Posted by in categories: life extension, mathematics, physics

Frank Jennings Tipler is a mathematical physicist and cosmologist, holding a joint appointment in the Departments of Mathematics and Physics at Tulane University. He holds a BS in Physics from MIT and a PhD from the University of Maryland.

Watch his interview below on eternal life. To watch more interviews on this topic, click here: https://bit.ly/2wcTT1N

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May 24, 2019

Exposure to air pollution before and after birth may affect fundamental cognitive abilities

Posted by in categories: education, health, mathematics, neuroscience, sustainability

A growing body of research suggests that exposure to air pollution in the earliest stages of life is associated with negative effects on cognitive abilities. A new study led by the Barcelona Institute for Global Health (ISGlobal), a centre supported by “la Caixa”, has provided new data: exposure to particulate matter with a diameter of less than 2.5 μm (PM2.5) during pregnancy and the first years of life is associated with a reduction in fundamental cognitive abilities, such as working memory and executive attention.

The study, carried out as part of the BREATHE project, has been published in Environmental Health Perspectives. The objective was to build on the knowledge generated by earlier studies carried out by the same team, which found lower levels of cognitive development in children attending schools with higher levels of traffic-related air pollution.

The study included 2,221 children between 7 and 10 years of age attending schools in the city of Barcelona. The children’s cognitive abilities were assessed using various computerized tests. Exposure to air pollution at home during pregnancy and throughout childhood was estimated with a mathematical model using real measurements.

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May 21, 2019

Mathematicians revive abandoned approach to the Riemann Hypothesis

Posted by in category: mathematics

Many ways to approach the Riemann Hypothesis have been proposed during the past 150 years, but none of them have led to conquering the most famous open problem in mathematics. A new paper in the Proceedings of the National Academy of Sciences (PNAS) suggests that one of these old approaches is more practical than previously realized.

“In a surprisingly short proof, we’ve shown that an old, abandoned approach to the Riemann Hypothesis should not have been forgotten,” says Ken Ono, a theorist at Emory University and co-author of the paper. “By simply formulating a proper framework for an old approach we’ve proven some new theorems, including a large chunk of a criterion which implies the Riemann Hypothesis. And our general framework also opens approaches to other basic unanswered questions.”

The paper builds on the work of Johan Jensen and George Pólya, two of the most important mathematicians of the 20th century. It reveals a method to calculate the Jensen-Pólya polynomials—a formulation of the Riemann Hypothesis—not one at a time, but all at once.

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May 17, 2019

Bristol mathematician cracks Diophantine puzzle

Posted by in categories: information science, mathematics

A mathematician from the University of Bristol has found a solution to part of a 64-year old mathematical problem – expressing the number 33 as the sum of three cubes.

Since the 1950s, mathematicians have wondered if all could be expressed as the sum of three cubes; whether the equation k = x³+ y³+ z³ always has a .

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