Quantum gravitation. Medical search. Frequent questions

I lecture modules on Quantum Mechanics A and Relativity & Gravitation, and supervise projects in relativity and cosmology. (qmul.ac.uk)
My research interests are in relativity, gravitation, and cosmology. (qmul.ac.uk)
William Unruh is renowned for pivotal contributions to the understanding of a range of subtle problems arising at the crossroads of quantum physics, gravitational theory and cosmology. (royalsociety.org)
It will be described how the world of gravitation and cosmology, as well as quantum theory and particle physics, arises from these considerations. (arxiv.org)
On top of our teaching duties, we carry out research activities which cover a wide range of topics in theoretical and mathematical aspects of quantum field theory, quantum mechanics, relativity, gravitation and cosmology. (ehu.es)
He does research on theoretical aspects of cosmology, field theory, gravitation, and quantum mechanics as well as work on dark matter and dark energy, modified gravity, topological defects, extra dimensions, and violations of fundamental symmetries. (equaltimeforfreethought.org)

Quantum gravity (QG) is a field of theoretical physics that seeks to describe gravity according to the principles of quantum mechanics. (wikipedia.org)
Unsolved problem in physics: How can the theory of quantum mechanics be merged with the theory of general relativity / gravitational force and remain correct at microscopic length scales? (wikipedia.org)
No theory has yet proven successful in describing the general situation where the dynamics of matter, modeled with quantum mechanics, affect the curvature of spacetime. (wikipedia.org)
any theory predating quantum mechanics that encompassed Planck's radiation law and a scheme for obtaining discrete energy states for atoms, such as the Bohr model . (dictionary.com)
Any of various theories that makes use of the assumptions, principles, and laws of quantum mechanics. (dictionary.com)
Some tests are concerned with the large mass limit of the quantum superposition principle, which forms the basis of quantum mechanics. (southampton.ac.uk)
Other experiments are concerned with testing the interplay between quantum mechanics and gravitation in the low energy limit. (southampton.ac.uk)
In the past I have taught Quantum Mechanics, Electromagnetism and Special Relativity at the universities of Cambridge and Oxford. (qmul.ac.uk)
We all know quantum mechanics explains precisely why electrons behave weirdly. (futurity.org)
S cience, from the immutable logic of its mathematical underpinnings to the more fluid realms of the social sciences, has carried us from our humble origins to an understanding of such esoteric notions as gravitation and quantum mechanics. (cerncourier.com)
Beyond physics, the subject makes direct contact with the study of the spectral and dynamical properties of non-selfadjoint operators, a very active area of current research in applied and fundamental mathematics with direct applications in physics, from hydrodynamics and turbulence to non-Hermitian quantum mechanics. (frontiersin.org)
i) Formulations of quasi-normal modes as a spectral non-selfadjoint problem with particular attention to hyperboloidal methods and spectral instability ii) Mathematical and physical aspects of other non-selfadjoint spectral problems iii) Application of the Pseudospectrum in spectral/dynamical settings in physics (gravitation, optics, fluids, quantum mechanics. (frontiersin.org)
The information that falls into a black hole has to be stored somewhere, or it would violate a law of quantum mechanics. (crystalinks.com)
But this would go against the laws of quantum mechanics: information can't be lost. (crystalinks.com)
In these classic lessons, Feynman introduces the general reader to the following topics: atoms, basic physics, energy, gravitation, quantum mechanics, and the relationship of physics to other topics. (polyteknisk.dk)

Quantum Gravity takes into accountability the forces of black holes, anti - radiation and energy that follows as a result of the interaction of three of the four forces of nature. (leanpub.com)
Finally the discrepancies between the predicted value for the vacuum energy and the observed values (which, depending on the considerations, can be of 60 or 120 orders of magnitude) highlight the necessity for a quantum theory of gravity. (wikipedia.org)
The field of quantum gravity is actively developing, and theorists are exploring a variety of approaches to the problem of quantum gravity, the most popular being M-theory and loop quantum gravity. (wikipedia.org)
However, many approaches to quantum gravity, such as string theory, try to develop a framework that describes all fundamental forces. (wikipedia.org)
One of the difficulties of formulating a quantum gravity theory is that direct observation of quantum gravitational effects is thought to only appear at length scales near the Planck scale, around 10−35 meters, a scale far smaller, and hence only accessible with far higher energies, than those currently available in high energy particle accelerators. (wikipedia.org)
Thought experiment approaches have been suggested as a testing tool for quantum gravity theories. (wikipedia.org)
In the field of quantum gravity there are several open questions - e.g., it is not known how spin of elementary particles sources gravity, and thought experiments could provide a pathway to explore possible resolutions to these questions, even in the absence of lab experiments or physical observations. (wikipedia.org)
In the early 21st century, new experiment designs and technologies have arisen which suggest that indirect approaches to testing quantum gravity may be feasible over the next few decades. (wikipedia.org)
This field of study is called phenomenological quantum gravity. (wikipedia.org)
What verifiable predictions does any theory of quantum gravity make? (wikipedia.org)
If one attempts to treat gravity as simply another quantum field, the resulting theory is not renormalizable. (wikipedia.org)
In this contribution to the Festschrift for Prof. Remo Ruffini, we investigate a formulation of quantum gravity using the Hořava-Lifshitz theory of gravity, which is General Relativity augmented by counter-terms to render the theory regularized. (mdpi.com)
The focus of investigation in the group of Quantum Field Theory and Gravity consists of three main strands: (1) Quantum field theory in curved spacetimes (Prof. Dr. R. Verch, Dr. T. P. Hack), (2) mathematical structure of gauge field theories and their quantization (Prof. Dr. G. Rudolph (retired), Dr. M. Schmidt) and (3) quantum fields under the influence of external conditions (PD Dr. M. Bordag). (uni-leipzig.de)
One of the aims is to gain a better understanding of essential ingredients for a potential theory of quantum gravity. (uni-leipzig.de)
For profound scientific questions, his research serves as a testbed for theoretical predictions and provides empirical evidence to explore possible limitations of quantum theory, such as those predicted by holographic duality and collapse models, and eventually, the interplay between quantum theory and gravity. (southampton.ac.uk)
John Wheeler, one of the world's most influential physicists, is best known for coining the term 'black holes', for his seminal contributions to the theories of quantum gravity and nuclear fission, as well as for his mind-stretching theories and writings on time, space and gravity. (webofstories.com)
I am a long standing member of the Gravitational Physics Group at the Institute of Physics, and am a member of the editorial board of Classical and Quantum Gravity. (qmul.ac.uk)
The terms gravitation and gravity are mostly interchangeable in everyday use, but in scientific usage a distinction may be made. (wikidoc.org)
Gravitation" is a general term describing the attractive influence that all objects with mass exert on each other, while "gravity" specifically refers to a force that is supposed in some theories (such as Newton's) to be the cause of this attraction. (wikidoc.org)

For that reason, researchers have developed a framework to describe quantum theory in combination with general relativity. (dictionary.com)
By contrast, in general relativity gravitation is due to spacetime curvatures that cause inertially moving objects to accelerate towards each other. (wikidoc.org)
But the quantum field theory, another leading theory of the 20th century that faithfully describes the world of particles and the infinitely small, would seem to be irreconcilable with general relativity. (oca.eu)
Certain candidate theories predict that the principle of the equivalence between gravitation and acceleration, at the heart of the theory of general relativity, could be violated at very weak levels. (oca.eu)

I mentioned string theory and quantum gravitation: one of the interests is that there is an equivalence between a theory of gravitation valid in AdS space and another theory valid only at the edge of this space. (polytechnique.edu)

In that way, it incorporates both classical physics and quantum theory to explain the most general range of phenomena yet. (dictionary.com)
Applying this new logic to phenomena such as gravitation and energy and theories of relativity and quantum new perspectives arise. (novapublishers.com)
The experimental characterisation of the quantum chips also proved that one of the strangest phenomena of the quantum world, namely "quantum entanglement", was achieved on-chip. (2physics.com)

and furthermore some aspects of quantum field theory on spacetimes that contain closed timelike curves. (uni-leipzig.de)

Quantum effects have a profound impact on the gauge field-driven cosmological evolution. (lu.se)

Balt van Rees, a researcher at the Center for Theoretical Physics, is interested in the mathematical framework of quantum field theories, which are used in many areas of physics, still raises many questions. (polytechnique.edu)
What are quantum field theories? (polytechnique.edu)
Quantum field theories (QFT) are used in many areas of physics. (polytechnique.edu)
QFT stands for quantum field theories. (polytechnique.edu)

It's strange that the two greatest developments of theoretical physics, the quantum theory and relativity, should take so long to come into a union. (webofstories.com)

In particular, a dynamical formation of the spatially-homogeneous and isotropic gauge field condensate may be responsible for both early and late-time acceleration, as well as for dynamical compensation of non-perturbative quantum vacua contributions to the ground state of the Universe. (lu.se)

all of which signal the collapse of the general theory of relativity at different scales and highlight the need for a gravitational theory that goes into the quantum realm. (wikipedia.org)

All of these approaches aim to describe the quantum behavior of the gravitational field, which does not necessarily include unifying all fundamental interactions into a single mathematical framework. (wikipedia.org)
On the other hand, quantum field theory is typically formulated in the flat spacetime used in special relativity. (wikipedia.org)
A sideline of this research is quantum field theory on non-commutative geometries. (uni-leipzig.de)
In quantum field theory under the influence of external conditions, a central research field is the influence of boundaries, as in the Casimir effect, and singular potentials and their role in quantization. (uni-leipzig.de)
Quantum field theory is not significantly affected until close to the horizon. (blogspot.com)
Despite these achievements, we still have only a rudimentary understanding of what a quantum field theory really is. (polytechnique.edu)
The idea of QFTinAdS is not to study a theory of quantum gravitation, but a quantum field theory in AdS space, such as the quantum field theory used to describe proton collisions. (polytechnique.edu)
It can be shown that at the edge of this space, this theory is similar to another quantum field theory that describes, for example, critical exponents. (polytechnique.edu)
Two kind of fluctuations sources are analyzed: quantum electromagnetic field thermal fluctuations and current fluctuations in the magnetic field generating circuit. (ndltd.org)
While observers are comfortable with taking the -term as an additional parameter, which considerably improves the CDM fits to the data, for theorists, the uniform positive and small -term raises plenty of issues and contradictions with the existing quantum field theory (QFT). (lu.se)

Here, we're applying quantum physics to something that is relatively big, a device that you can see under an optical microscope, and we're seeing the quantum effects in a trillion atoms instead of just one. (futurity.org)

Indeed, the recent introduction of the Pseudospectrum in gravitation physics, namely in the study of the spectral instability of quasi-normal modes of black holes, has raised a number of questions that remain open and are urgent to answer in the context of astrophysical compact objects as sources of gravitational waves. (frontiersin.org)

At distances close to the Planck length, like those near the center of the black hole, quantum fluctuations of spacetime are expected to play an important role. (wikipedia.org)

The Ulbricht group performs quantum experimental research on the preparation and analysis of massive systems in non-classical states by various techniques. (southampton.ac.uk)

The formalism was originally developed in the 1930s to combine the principles of quantum physics with those of the theory of special relativity. (polytechnique.edu)

But we know that even at the quantum ground state, at zero-temperature, very small amplitude fluctuations-or noise-remain. (futurity.org)
We showed that we can actually make the fluctuations of one of the variables smaller-at the expense of making the quantum fluctuations of the other variable larger. (futurity.org)

The basic problem, however, is to describe various quantum vacuum (condensate) contributions to the ground state energy at macroscopic separations (IR limit), as well as their renormalization group (RG) running without having a complete high-energy QFT (UV limit). (lu.se)

The ability to control quantum noise could one day be used to improve the precision of very sensitive measurements, such as those obtained by LIGO, the Laser Interferometry Gravitational-wave Observatory, a Caltech-and-MIT-led project searching for signs of gravitational waves, ripples in the fabric of space-time. (futurity.org)

This approach is useful for proof of principle quantum logic operation, however, photonic quantum technologies will require scalable, miniaturized gates, with improved performances. (2physics.com)

Modern physics describes gravitation using the general theory of relativity , but the much simpler Newton's law of universal gravitation provides an excellent approximation in most cases. (wikidoc.org)

Researchers have figured out how to observe and control this movement, known as quantum motion or noise. (futurity.org)
Because this quantum motion is theoretically an intrinsic part of the motion of all objects, Schwab and his colleagues designed a device that would allow them to observe this noise and then manipulate it. (futurity.org)

quantum theory explains the small stuff, where matter and energy divide into infinitesimal particles. (dictionary.com)
a theory concerning the behaviour of physical systems based on Planck's idea that they can only possess certain properties, such as energy and angular momentum, in discrete amounts (quanta). (dictionary.com)
This energy is part of the quantum description of nature-you just can't get it out," says Keith Schwab. (futurity.org)
Instead, the residual energy-quantum noise-remained. (futurity.org)

Coauthors Aashish Clerk from McGill University and Florian Marquardt from the Max Planck Institute for the Science of Light proposed a novel method to control the quantum noise, which was expected to reduce it periodically. (futurity.org)

It is also a tool in string theory that seeks to reconcile gravitation with quantum physics. (polytechnique.edu)

In this short review, I discuss basic qualitative characteristics of quantum non-Abelian gauge dynamics in the non-stationary background of the expanding Universe in the framework of the standard Einstein-Yang-Mills formulation. (lu.se)

Gravitation is a natural phenomenon by which all objects with mass attract each other, and is one of the fundamental forces of physics. (wikidoc.org)
Because this noisy quantum motion is always present and cannot be removed, it places a fundamental limit on how precisely one can measure the position of an object. (futurity.org)
Two photons interaction is a fundamental task for quantum information processing, and it is at the heart of the Controlled-NOT (CNOT) gate -one of the building block of a future quantum computer. (2physics.com)

BTW gravitation is a very weak actor, even with very large bodies. (nimblebrain.net)
Assumption three is a quite weak version of knowing that quantum gravitational effects can't just pop up anywhere in space that is almost flat. (blogspot.com)

Sending pairs of single photons in the two inputs of the directional coupler, it was possible to demonstrate the quantum interference effect, with a very high visibility of the quantum behaviour. (2physics.com)

Quantum information science has shown that quantum mechanical effects can dramatically improve performance for certain tasks in communication, computation and measurement. (2physics.com)

Polarized quantum vacuum as a player in gravitation. (nimblebrain.net)
If my notion is correct, embedding matter in space drives the emergence of gravitation, as a result of the nature of the quantum vacuum. (nimblebrain.net)
If gravitational repulsion between matter and antimatter is not observed, then we should look to quantum effects in the vacuum to provide polarization. (nimblebrain.net)

It deals with environments in which neither gravitational nor quantum effects can be ignored, such as in the vicinity of black holes or similar compact astrophysical objects, such as neutron stars as well as in the early stages of the universe moments after the Big Bang. (wikipedia.org)

For these reasons photons have been widely used in quantum communication, quantum metrology, and quantum lithography settings, as well as quantum bits (or qubits) for quantum information processing [1]. (2physics.com)

Quantum theory suggests that the three observed gauge groups U(1), SU(2) and SU(3) are related to the three Reidemeister moves of knot theory: twists, pokes and slides. (researchgate.net)

We are familiar with the existing views of the world of today, e.g. the theory of quantum, the theory of relativity, the table of elements, the standard model, different ideologies and religions. (novapublishers.com)
In the past couple of years, my group and a couple of other groups around the world have learned how to cool the motion of a small micrometer-scale object to produce this state at the bottom, or the quantum ground state," says Keith Schwab, a Caltech professor of physics and applied physics, who led the study published in Science . (futurity.org)

In this volume new answers to old questions are presented, e.g. how the role of transformers replaces black holes, ATP synthase, the photoelectric effect and one equation that unites relativity and quantum. (novapublishers.com)

Look up gravitation in Wiktionary, the free dictionary. (wikidoc.org)

how to unite the theory of relativity and the theory of quantum physics, the too complex standard model, the too static table of elements and the too simplistic theory of evolution within science. (novapublishers.com)

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