Notes - Personal Homepages
... The first is about the unification of the 4 known fundamental forces in nature. Three of them, the electro-magnetic, weak and strong nuclear forces belong to a common frame-work, quantum field theory and are reasonably well-unified in the context of the standard model of particle physics, whose adva ...
... The first is about the unification of the 4 known fundamental forces in nature. Three of them, the electro-magnetic, weak and strong nuclear forces belong to a common frame-work, quantum field theory and are reasonably well-unified in the context of the standard model of particle physics, whose adva ...
UNSTRUNG
... String theory came into existence by accident. In the late nineteen-sixties, a couple of young physicists thumbing through mathematics books came upon a centuries-old formula that, miraculously, seemed to fit the latest experimental data about elementary particles. At first, no one had a clue why th ...
... String theory came into existence by accident. In the late nineteen-sixties, a couple of young physicists thumbing through mathematics books came upon a centuries-old formula that, miraculously, seemed to fit the latest experimental data about elementary particles. At first, no one had a clue why th ...
NonequilibriumDynamicsofQuarkGluonPlasma
... •View Boltzmann equation as an effective theory with Quantum Fluctuations integrated out. •On the scale O(T), the dispersion relation of the hard particles is suppressed by O(g2) and collisions can be treated as local collisions. ...
... •View Boltzmann equation as an effective theory with Quantum Fluctuations integrated out. •On the scale O(T), the dispersion relation of the hard particles is suppressed by O(g2) and collisions can be treated as local collisions. ...
![Weak measurements [1] Pre and Post selection in strong measurements](http://s1.studyres.com/store/data/008913441_1-7a0f5f5a1778eb5da686e2de8a47882f-300x300.png)
It is widespread, if not common, belief that time
... in a reversed order whatever time sequence of actual occurrences. The pseudo-scalar nature of time, until now considered as a working hypothesis, may be easily recognized in the Minkowski space-time. For such a pseudo-euclidean space-time, the determinant of the metric tensor components g is negativ ...
... in a reversed order whatever time sequence of actual occurrences. The pseudo-scalar nature of time, until now considered as a working hypothesis, may be easily recognized in the Minkowski space-time. For such a pseudo-euclidean space-time, the determinant of the metric tensor components g is negativ ...
Representation Theory, Symmetry, and Quantum
... In the early 20th century, it had become apparent to physicists that many phenomena, from the orbiting of electrons in atoms to the emission and absorption of light waves, did not occur on a continuous spectrum, as classical theories would predict. Einstein’s 1905 discovery of the photoelectic effec ...
... In the early 20th century, it had become apparent to physicists that many phenomena, from the orbiting of electrons in atoms to the emission and absorption of light waves, did not occur on a continuous spectrum, as classical theories would predict. Einstein’s 1905 discovery of the photoelectic effec ...
Reverse Engineer Relativity, Quantum Mechanics and the Standard
... developed into a vision of a possible unified physics theory where all its parts emerge from one or two simple, more natural physical assumptions. It is in contrast to this vision that present day physics appears grossly and unnecessarily complicated. A case in point is how (QM) and (GR) have no com ...
... developed into a vision of a possible unified physics theory where all its parts emerge from one or two simple, more natural physical assumptions. It is in contrast to this vision that present day physics appears grossly and unnecessarily complicated. A case in point is how (QM) and (GR) have no com ...
Slides2 - WordPress.com
... In 2012, Polchinski tried to do calculations from a new path which ultimately leaded to a different end for this story! He showed that because of quantum effects, the event horizon is a very hot soup of particles called “firewall” which will burn every thing near it immediately. The first sacrifice ...
... In 2012, Polchinski tried to do calculations from a new path which ultimately leaded to a different end for this story! He showed that because of quantum effects, the event horizon is a very hot soup of particles called “firewall” which will burn every thing near it immediately. The first sacrifice ...
LanZ_0112_eps(1).
... This thesis explores Feynman’s idea of quantum simulations by using ultracold quantum gases. In the first part of the thesis we develop a general method applicable to atoms or molecules or even nanoparticles, to decelerate a hot fast gas beam to zero velocity by using an optical cavity. This deceler ...
... This thesis explores Feynman’s idea of quantum simulations by using ultracold quantum gases. In the first part of the thesis we develop a general method applicable to atoms or molecules or even nanoparticles, to decelerate a hot fast gas beam to zero velocity by using an optical cavity. This deceler ...
Cosmology in the Laboratory (COSLAB)
... This connection allows us to simulate the least understood features of high energy physics and cosmology: the properties of the quantum vacuum. In particular, the vacuum energy estimated using the methods of particle physics is now in huge disagreement with modern cosmological experiments. This is t ...
... This connection allows us to simulate the least understood features of high energy physics and cosmology: the properties of the quantum vacuum. In particular, the vacuum energy estimated using the methods of particle physics is now in huge disagreement with modern cosmological experiments. This is t ...
Loop Quantum Gravity and Effective Matter Theories
... insist to apply a perturbative approach in gravity by replacing GR at high energies, just like Fermi theory was replaced by electroweak theory, then the main objection is that metric splitting and background dependence, implicit in perturbation theory, means to lose active diffeomorphism invariance ...
... insist to apply a perturbative approach in gravity by replacing GR at high energies, just like Fermi theory was replaced by electroweak theory, then the main objection is that metric splitting and background dependence, implicit in perturbation theory, means to lose active diffeomorphism invariance ...
A first view on the mathematical structure of the standard
... finding every single particle that for all intents and purposes plays a role in our life. We have developed a new theory to describes all known elementary particles and the interaction between them, including the strong, the weak and the electromagnetic interaction. One fundamental component is the ...
... finding every single particle that for all intents and purposes plays a role in our life. We have developed a new theory to describes all known elementary particles and the interaction between them, including the strong, the weak and the electromagnetic interaction. One fundamental component is the ...
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.