Book of Abstracts
... sensitivity and a spurt of quantum gravity models that do not respect the local spacetime symmetries familiar from the standard model. As a result of this intense research focus there is now a theoretical zoo, with multiple theories that modify Lorentz symmetry in very different ways, as well as an ...
... sensitivity and a spurt of quantum gravity models that do not respect the local spacetime symmetries familiar from the standard model. As a result of this intense research focus there is now a theoretical zoo, with multiple theories that modify Lorentz symmetry in very different ways, as well as an ...
Quantum gravitational contributions to quantum electrodynamics
... this result have been considered 14 . The potential importance of the original calculation 13 stimulated a number of further investigations that cast doubt on its findings. It was shown 15 that a different choice of gauge condition led to the absence of any quantum gravity correction to the Yang-Mil ...
... this result have been considered 14 . The potential importance of the original calculation 13 stimulated a number of further investigations that cast doubt on its findings. It was shown 15 that a different choice of gauge condition led to the absence of any quantum gravity correction to the Yang-Mil ...
Unweaving the Fabric of the Universe: The Interplay between
... data. The early universe was extremely hot, so that there were no atoms, but only free electrons and nuclei. The free electrons acted as glue between photons and baryons through Thomson scattering. Hence at very early times, the universe was filled with a cosmological plasma of a tightly coupled pho ...
... data. The early universe was extremely hot, so that there were no atoms, but only free electrons and nuclei. The free electrons acted as glue between photons and baryons through Thomson scattering. Hence at very early times, the universe was filled with a cosmological plasma of a tightly coupled pho ...
Chapter 1 Introduction
... explained and that physics had already achieved its task: to describe nature at the fundamental level in a mathematical form. All that was seen and observed in nature seemed compatible with classical physics. In those days it was not uncommon at all to think that the study of physics was essentially ...
... explained and that physics had already achieved its task: to describe nature at the fundamental level in a mathematical form. All that was seen and observed in nature seemed compatible with classical physics. In those days it was not uncommon at all to think that the study of physics was essentially ...
The Weak and Strong Nuclear Interactions
... These bosons had companions called Higgs bosons whose role is to explain the origin and value of the mass of the elementary particles. All of these particles, with the exception of the Higgs bosons, have been discovered. In 1978 the Standard Model (SM), a collection of established experimental knowl ...
... These bosons had companions called Higgs bosons whose role is to explain the origin and value of the mass of the elementary particles. All of these particles, with the exception of the Higgs bosons, have been discovered. In 1978 the Standard Model (SM), a collection of established experimental knowl ...
A1993LX38200001
... We had fun correlating classical and quantum behavior in scattering, and before long had produced a series of three papers. The first, with coauthors D.L. Hill and M. Wakano, explored special features of barrier penetration. The second (the one under discussion here) provided general methodology for ...
... We had fun correlating classical and quantum behavior in scattering, and before long had produced a series of three papers. The first, with coauthors D.L. Hill and M. Wakano, explored special features of barrier penetration. The second (the one under discussion here) provided general methodology for ...
University of Groningen M-theory and gauged supergravities Roest
... In string theory, elementary particles are replaced by small strings of Planck size. These strings can vibrate in different ways. However, since the strings are so small, we cannot see their extended character and their vibration: the different vibrational modes are interpreted as different elementa ...
... In string theory, elementary particles are replaced by small strings of Planck size. These strings can vibrate in different ways. However, since the strings are so small, we cannot see their extended character and their vibration: the different vibrational modes are interpreted as different elementa ...
text - Physics Department, Princeton University
... however, it is in many situations possible to accurately quantify our ignorance. And as a famous epistemologist, the former US defense secretary Donald Rumsfeld, once highlighted, it is much better deal with ’known unknowns’ than with ’unknown unknowns’. The degree of ignorance goes by the name ‘en ...
... however, it is in many situations possible to accurately quantify our ignorance. And as a famous epistemologist, the former US defense secretary Donald Rumsfeld, once highlighted, it is much better deal with ’known unknowns’ than with ’unknown unknowns’. The degree of ignorance goes by the name ‘en ...
Fulltext PDF
... QCD sector. Both quarks and gluons are not seen directly in any experiment. They are supposed to be permanently con¯ned inside the proton and neutron. But this hypothesis of con¯nement which is supposed to be a property of QCD has not been proved. This important theoretical challenge remains as a lo ...
... QCD sector. Both quarks and gluons are not seen directly in any experiment. They are supposed to be permanently con¯ned inside the proton and neutron. But this hypothesis of con¯nement which is supposed to be a property of QCD has not been proved. This important theoretical challenge remains as a lo ...
Gregory Moore - Rutgers Physics
... satisfy a system of integral equations formally identical to Zamolodchikov’s Thermodynamic Bethe Ansatz One of many relations to integrable systems… ...
... satisfy a system of integral equations formally identical to Zamolodchikov’s Thermodynamic Bethe Ansatz One of many relations to integrable systems… ...
NMP_Paper 1_String Theory
... mathematical concepts and as Dr. Michael Dine points out “If you ask different string theorists what string theory is, you’ll get different answers.” (Henderson 2) but the general elements can be established1. String theory starts at an unimaginably small level, the constituents of the particles th ...
... mathematical concepts and as Dr. Michael Dine points out “If you ask different string theorists what string theory is, you’ll get different answers.” (Henderson 2) but the general elements can be established1. String theory starts at an unimaginably small level, the constituents of the particles th ...
Why Does Space Exist?
... Is it valid to think of Euler’s constant as a link between continuum mathematics and non-continuum mathematics? What are the most profound symmetries in the mathematics of continua and in the mathematics of lattices? “Many problems in quantum mechanics are characterised by discrete symmetries. At th ...
... Is it valid to think of Euler’s constant as a link between continuum mathematics and non-continuum mathematics? What are the most profound symmetries in the mathematics of continua and in the mathematics of lattices? “Many problems in quantum mechanics are characterised by discrete symmetries. At th ...
String theory to the rescue - KITP - University of California, Santa
... determining the form of the Einstein equation. Of course, the cosmological constant was a confusion, and the equation does not describe matter, but more importantly the restriction to terms linear in the curvature was artificial. The equivalence principle allows terms quadratic in the curvature, cub ...
... determining the form of the Einstein equation. Of course, the cosmological constant was a confusion, and the equation does not describe matter, but more importantly the restriction to terms linear in the curvature was artificial. The equivalence principle allows terms quadratic in the curvature, cub ...
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.