Quantum Fields and Fundamental Geometry
... Is there a way to be sure that classical physics is right? ...
... Is there a way to be sure that classical physics is right? ...
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... Namely- the one drawn up by string theory. String theory is the most widely known candidate in the search for a TOE. And with good reason. It has elegance. The messy array of particles that make up matter and forces (including Gravity) can be pared down to vibrations of infinitesimal strings. It has ...
... Namely- the one drawn up by string theory. String theory is the most widely known candidate in the search for a TOE. And with good reason. It has elegance. The messy array of particles that make up matter and forces (including Gravity) can be pared down to vibrations of infinitesimal strings. It has ...
The Department of Applied Physics (http://physics
... gravity and superfluid 3He. The project combines theoretical and experimental efforts. We expect to hire one researcher with theoretical background and experience in a team work with experimentalists and one with experimental skills, preferably in superfluid 3He. For more information please contact ...
... gravity and superfluid 3He. The project combines theoretical and experimental efforts. We expect to hire one researcher with theoretical background and experience in a team work with experimentalists and one with experimental skills, preferably in superfluid 3He. For more information please contact ...
Matteo Bertolini: Research
... have a two-fold nature. On the one hand their dynamics, at low energy, can be described in terms of gauge theory degrees of freedom. On the other hand, they are solitons in string theory and, as such, they arise as classical solutions of the low-energy effective theory and curve space-time. The abov ...
... have a two-fold nature. On the one hand their dynamics, at low energy, can be described in terms of gauge theory degrees of freedom. On the other hand, they are solitons in string theory and, as such, they arise as classical solutions of the low-energy effective theory and curve space-time. The abov ...
Why quantum gravity? - University of Oxford
... of Mercury; to the evolution of the universe and the cosmic microwave background. More recently discrepancies have been found in large distance physics and at present these are the subject of intense activity. We do not know for sure what will have to be modified; whether general relativity itself o ...
... of Mercury; to the evolution of the universe and the cosmic microwave background. More recently discrepancies have been found in large distance physics and at present these are the subject of intense activity. We do not know for sure what will have to be modified; whether general relativity itself o ...
From the Big Bang to String Theory
... It’s kind of like the old maps drawn by sailors. Sailors have pretty vivid imaginations. They might see a pod of whales from a distance, and not recognize it for what it was. So they would come up with an explanation for what they were seeing – the curves of a sea serpent. Then they would draw some ...
... It’s kind of like the old maps drawn by sailors. Sailors have pretty vivid imaginations. They might see a pod of whales from a distance, and not recognize it for what it was. So they would come up with an explanation for what they were seeing – the curves of a sea serpent. Then they would draw some ...
list of abstracts - Faculdade de Ciências
... Based on a family of indefinite unitary representations of the diffeomorphism group of an oriented smooth 4-manifold, a manifestly covariant 4dimensional and non-perturbative algebraic quantum field theory formulation of gravity is exhibited. More precisely among the bounded linear operators acting ...
... Based on a family of indefinite unitary representations of the diffeomorphism group of an oriented smooth 4-manifold, a manifestly covariant 4dimensional and non-perturbative algebraic quantum field theory formulation of gravity is exhibited. More precisely among the bounded linear operators acting ...
Quantum mechanics is the theory that we use to describe the
... between general relativity and quantum mechanics is the graviton. This as yet undetected particle is a spin two particle, meaning two times H BAR. CHECK. Let’s look at what quantum mechanics has to say about the fundamental forces. We have known since Newton’s time what forces are. A force can basic ...
... between general relativity and quantum mechanics is the graviton. This as yet undetected particle is a spin two particle, meaning two times H BAR. CHECK. Let’s look at what quantum mechanics has to say about the fundamental forces. We have known since Newton’s time what forces are. A force can basic ...
Daniel Heineman Prize: The Quest for Quantum Gravity
... Is there one theory of quantum gravity or many? • If one imposes only two of the three consistency conditions, one can find many theories of quantum gravity. • Many attempts give up Lorentz invariance at the start, and it has even been argued that this is a necessary feature of quantum gravity. • I ...
... Is there one theory of quantum gravity or many? • If one imposes only two of the three consistency conditions, one can find many theories of quantum gravity. • Many attempts give up Lorentz invariance at the start, and it has even been argued that this is a necessary feature of quantum gravity. • I ...
26-06-2015-Juan-Maldacena (2)
... Black holes and hydrodynamics • Field theory at finite temperature = black brane in Anti-de-Sitter space Ripples on the black brane = ...
... Black holes and hydrodynamics • Field theory at finite temperature = black brane in Anti-de-Sitter space Ripples on the black brane = ...
A path towards quantum gravity
... Type-I gauge theories • These equations define type-I gauge theories (e.g. Maxwell, Yang—Mills, Einstein). • All these theories, being gauge theories, need supplementary conditions, since the second functional derivative of S is not an invertible operator. After imposing such conditions, the theori ...
... Type-I gauge theories • These equations define type-I gauge theories (e.g. Maxwell, Yang—Mills, Einstein). • All these theories, being gauge theories, need supplementary conditions, since the second functional derivative of S is not an invertible operator. After imposing such conditions, the theori ...
Quantum gravity
Quantum gravity (QG) is a field of theoretical physics that seeks to describe the force of gravity according to the principles of quantum mechanics.The current understanding of gravity is based on Albert Einstein's general theory of relativity, which is formulated within the framework of classical physics. On the other hand, the nongravitational forces are described within the framework of quantum mechanics, a radically different formalism for describing physical phenomena based on probability. The necessity of a quantum mechanical description of gravity follows from the fact that one cannot consistently couple a classical system to a quantum one.Although a quantum theory of gravity is needed in order to reconcile general relativity with the principles of quantum mechanics, difficulties arise when one attempts to apply the usual prescriptions of quantum field theory to the force of gravity. From a technical point of view, the problem is that the theory one gets in this way is not renormalizable and therefore cannot be used to make meaningful physical predictions. As a result, theorists have taken up more radical approaches to the problem of quantum gravity, the most popular approaches being string theory and loop quantum gravity. A recent development is the theory of causal fermion systems which gives quantum mechanics, general relativity, and quantum field theory as limiting cases.Strictly speaking, the aim of quantum gravity is only to describe the quantum behavior of the gravitational field and should not be confused with the objective of unifying all fundamental interactions into a single mathematical framework. While any substantial improvement into the present understanding of gravity would aid further work towards unification, study of quantum gravity is a field in it's own right with various branches having different approaches to unification. Although some quantum gravity theories, such as string theory, try to unify gravity with the other fundamental forces, others, such as loop quantum gravity, make no such attempt; instead, they make an effort to quantize the gravitational field while it is kept separate from the other forces. A theory of quantum gravity that is also a grand unification of all known interactions is sometimes referred to as a theory of everything (TOE).One of the difficulties of quantum gravity is that quantum gravitational effects are only expected to become apparent near the Planck scale, a scale far smaller in distance (equivalently, far larger in energy) than what is currently accessible at high energy particle accelerators. As a result, quantum gravity is a mainly theoretical enterprise, although there are speculations about how quantum gravity effects might be observed in existing experiments.