Physics meets philosophy at the Planck scale: Contemporary

... in the business of providing an accurate picture of reality in any deeper sense. Since there are currently no observations demanding a quantum gravitational theory, it might be thought that advocates of such a position would view the endeavour as empty and misguided speculation, perhaps of formal in ...

... in the business of providing an accurate picture of reality in any deeper sense. Since there are currently no observations demanding a quantum gravitational theory, it might be thought that advocates of such a position would view the endeavour as empty and misguided speculation, perhaps of formal in ...

Approaches to Quantum Gravity

... version, i.e. spin foam models). Alongside them, we have various (and rather different in both spirit and techniques used) discrete approaches, represented here by simplicial quantum gravity, in particular the recent direction of causal dynamical triangulations, quantum Regge calculus, and the “cons ...

... version, i.e. spin foam models). Alongside them, we have various (and rather different in both spirit and techniques used) discrete approaches, represented here by simplicial quantum gravity, in particular the recent direction of causal dynamical triangulations, quantum Regge calculus, and the “cons ...

Can Renormalization Change the Observable Predictions of Inflation? Gonzalo J. Olmo

... Little attention has been paid to these divergences: ◆ Sometimes this is bypassed by regarding h(~x,t) as a classical random field and introducing a window function to remove the Fourier modes with large k. But QFT is much more than Quantum Mechanics. ...

... Little attention has been paid to these divergences: ◆ Sometimes this is bypassed by regarding h(~x,t) as a classical random field and introducing a window function to remove the Fourier modes with large k. But QFT is much more than Quantum Mechanics. ...

Gauge symmetries in Quantum Gravity and String Theory

... This thesis explores the spectrum of states charged under global and gauge symmetries in String Theory, and the constraints that they pose on specific phenomenological models. On one hand, we use supercritical theories (those with more than 10 or 26 dimensions) to embed discrete gauge symmetries of ...

... This thesis explores the spectrum of states charged under global and gauge symmetries in String Theory, and the constraints that they pose on specific phenomenological models. On one hand, we use supercritical theories (those with more than 10 or 26 dimensions) to embed discrete gauge symmetries of ...

Lectures on Conformal Field Theory arXiv:1511.04074v2 [hep

... Yet another familiar theory is the classical λφ4 theory in d = 4 dimensions with equation of motion ∂ 2 φ = λφ3 /3! Even with interactions, however, the associated Lagrangians describe massless fields. This is because a theory cannot be conformally invariant if the Lagrangian has some mass parameter ...

... Yet another familiar theory is the classical λφ4 theory in d = 4 dimensions with equation of motion ∂ 2 φ = λφ3 /3! Even with interactions, however, the associated Lagrangians describe massless fields. This is because a theory cannot be conformally invariant if the Lagrangian has some mass parameter ...

- Free Documents

... of work that followed, it became clear that a useful framework for under standing this situation is Atiyahs axiomatic description of a topological quantum eld theory, or TQFT. On the other hand, at about the same time as Jones initial discov ery, Ashtekar discovered a reformulation of general relati ...

... of work that followed, it became clear that a useful framework for under standing this situation is Atiyahs axiomatic description of a topological quantum eld theory, or TQFT. On the other hand, at about the same time as Jones initial discov ery, Ashtekar discovered a reformulation of general relati ...

Kuhn Losses Regained: Van Vleck from Spectra to

... By the time he wrote his article in Chemical Reviews, Van Vleck had come to recognize that a strong argument against the old and in favor of the new quantum theory could be found in the theory of susceptibilities, a subject of marginal interest during the reign of the old quantum theory. As he wrot ...

... By the time he wrote his article in Chemical Reviews, Van Vleck had come to recognize that a strong argument against the old and in favor of the new quantum theory could be found in the theory of susceptibilities, a subject of marginal interest during the reign of the old quantum theory. As he wrot ...

gravity theory based on mass–energy equivalence

... The mass density field differs from those in current theories of gravity since it includes negative values and must be integrated to infinity. We interpreted the negative values as resulting from rest mass waves and kinetic energy waves in the FS. The speed of an object is defined relative to the FS ...

... The mass density field differs from those in current theories of gravity since it includes negative values and must be integrated to infinity. We interpreted the negative values as resulting from rest mass waves and kinetic energy waves in the FS. The speed of an object is defined relative to the FS ...

Spin Foam Models of Quantum Spacetime

... Relativity in terms of the Ashtekar variables [12]. In recent years many different approaches on the non-perturbative and background-independent side have been converging to the formalism of the so-called spin foams [13, 14, 15], and this class of models in the subject of this thesis. Why do we want ...

... Relativity in terms of the Ashtekar variables [12]. In recent years many different approaches on the non-perturbative and background-independent side have been converging to the formalism of the so-called spin foams [13, 14, 15], and this class of models in the subject of this thesis. Why do we want ...

Axial gravity, massless fermions and trace anomalies

... subject has been already treated in [1, 2]. The second, to our best knowledge, is new. The motivation for reconsidering the former is to clarify the theoretical background underlying the approach and complete the calculation of the anomaly, also in view of more recent results, [3]. For some aspects ...

... subject has been already treated in [1, 2]. The second, to our best knowledge, is new. The motivation for reconsidering the former is to clarify the theoretical background underlying the approach and complete the calculation of the anomaly, also in view of more recent results, [3]. For some aspects ...

slides

... Group Field Theories: spacetime from quantum discreteness to an amergent continuum – p. 4/3 models, simplicial QG,... ...

... Group Field Theories: spacetime from quantum discreteness to an amergent continuum – p. 4/3 models, simplicial QG,... ...

Classical and Quantum Features of String Cosmology

... with gravity. We apply them to classify all solutions with controlled chaos for the heterotic superstring theory. This chapter represents recent work that has not yet ...

... with gravity. We apply them to classify all solutions with controlled chaos for the heterotic superstring theory. This chapter represents recent work that has not yet ...

From Principles to Diagrams

... Kähler action plus cosmological term. This brings in the radii of spheres S 2 (M 4 ) and S 2 (CP2 ) associated with the twistors space of M 4 and CP2 . For S(CP2 ) the radius is of order CP2 radius R. R(S 2 (M 4 )) could be of the order of Planck length lP , which would thus become purely classical ...

... Kähler action plus cosmological term. This brings in the radii of spheres S 2 (M 4 ) and S 2 (CP2 ) associated with the twistors space of M 4 and CP2 . For S(CP2 ) the radius is of order CP2 radius R. R(S 2 (M 4 )) could be of the order of Planck length lP , which would thus become purely classical ...

The AdS 3/CFT2 correspondence in black hole physics

... with the current methods, the only familiar case of a black hole that can be treated strictly is the extremal Reissner-Nordstrøm solution when embedded in an N ≥ 2 supergravity theory, since it is known to support one Killing spinor. This has been extended to near extremal cases as well, but a full ...

... with the current methods, the only familiar case of a black hole that can be treated strictly is the extremal Reissner-Nordstrøm solution when embedded in an N ≥ 2 supergravity theory, since it is known to support one Killing spinor. This has been extended to near extremal cases as well, but a full ...

String Theory

... make up our universe. It also gives the only presently credible explanation for the value of the cosmological constant although, in fairness, I should add that the explanation is so distasteful to some that the community is rather amusingly split between whether this is a good thing or a bad thing. ...

... make up our universe. It also gives the only presently credible explanation for the value of the cosmological constant although, in fairness, I should add that the explanation is so distasteful to some that the community is rather amusingly split between whether this is a good thing or a bad thing. ...

Geophysics :: 1. Gravity methods

... the ellipsoid (the difference between the geocentric and geographic latitude is very small, reaching its maximum a latitude of 45° and it amounts to 0.19°). Applied geophysicists have used this relationship for the determination gravity distribution at the sea level and for normal correction. The fi ...

... the ellipsoid (the difference between the geocentric and geographic latitude is very small, reaching its maximum a latitude of 45° and it amounts to 0.19°). Applied geophysicists have used this relationship for the determination gravity distribution at the sea level and for normal correction. The fi ...

String Theory - damtp - University of Cambridge

... Reason 2. String theory may be the theory of quantum gravity With broad brush, string theory looks like an extremely good candidate to describe the real world. At low-energies it naturally gives rise to general relativity, gauge theories, scalar fields and chiral fermions. In other words, it contai ...

... Reason 2. String theory may be the theory of quantum gravity With broad brush, string theory looks like an extremely good candidate to describe the real world. At low-energies it naturally gives rise to general relativity, gauge theories, scalar fields and chiral fermions. In other words, it contai ...

"Loop Quantum Gravity" (Rovelli)

... For a relativist, on the other hand, the idea of a fundamental description of gravity in terms of physical excitations over a background space sounds physically wrong. The key lesson learned from general relativity is that there is no background metric space over which physics happens (except, of co ...

... For a relativist, on the other hand, the idea of a fundamental description of gravity in terms of physical excitations over a background space sounds physically wrong. The key lesson learned from general relativity is that there is no background metric space over which physics happens (except, of co ...

Haag`s Theorem in Renormalisable Quantum Field Theories

... divergences encountered there were cured by a finite number of subtractions, once the appropriate counterterms had been identified [GliJaf68, GliJaf70]. • Fourth, however, these problems exacerbated to serious and to this day unsurmountable obstructions as soon as the realm of renormalisable theorie ...

... divergences encountered there were cured by a finite number of subtractions, once the appropriate counterterms had been identified [GliJaf68, GliJaf70]. • Fourth, however, these problems exacerbated to serious and to this day unsurmountable obstructions as soon as the realm of renormalisable theorie ...

How do you divide your (two dimensional) time? .1in SLE, CLE, the

... “There are methods and formulae in science, which serve as masterkeys to many apparently different problems. The resources of such things have to be refilled from time to time. In my opinion at the present time we have to develop an art of handling sums over random surfaces. These sums replace the ...

... “There are methods and formulae in science, which serve as masterkeys to many apparently different problems. The resources of such things have to be refilled from time to time. In my opinion at the present time we have to develop an art of handling sums over random surfaces. These sums replace the ...

Discrete Approaches to Quantum Gravity in Four Dimensions

... of quantum gravity in four dimensions via an intermediate discretization. I will only discuss models with some concrete implementation of the dynamics of Einstein’s theory, Lagrangian or Hamiltonian. One way of tackling the quantization problem non-perturbatively is to use discrete methods, in analo ...

... of quantum gravity in four dimensions via an intermediate discretization. I will only discuss models with some concrete implementation of the dynamics of Einstein’s theory, Lagrangian or Hamiltonian. One way of tackling the quantization problem non-perturbatively is to use discrete methods, in analo ...

The Mathematics of the Casimir Effect

... On the Whole, Divergent Series are the Works of the Devil and it’s a Shame that one dares base any Demonstration upon them. You can get whatever result you want when you use them, and they have given rise to so many Disasters and so many Paradoxes. Can anything more horrible be conceived than to hav ...

... On the Whole, Divergent Series are the Works of the Devil and it’s a Shame that one dares base any Demonstration upon them. You can get whatever result you want when you use them, and they have given rise to so many Disasters and so many Paradoxes. Can anything more horrible be conceived than to hav ...

Effective Field Theory

... are integrated out from the action. One gets in this way a string of nonrenormalizable interactions among the light states, which can be organized as an expansion in powers of energy/Λ. The information on the heavier degrees of freedom is then contained in the couplings of the resulting lowenergy La ...

... are integrated out from the action. One gets in this way a string of nonrenormalizable interactions among the light states, which can be organized as an expansion in powers of energy/Λ. The information on the heavier degrees of freedom is then contained in the couplings of the resulting lowenergy La ...

Widening the Axion Window via Kinetic and Stückelberg Mixings

... PACS numbers: 14.80.Va, 11.25.Wx, 95.35.+d, 98.80.Cq ...

... PACS numbers: 14.80.Va, 11.25.Wx, 95.35.+d, 98.80.Cq ...

The AdS/CMT manual for plumbers and electricians

... Eddington had a thorough understanding of the theory itself, as required to design the observations putting Einstein on the real axis of empirical reality. Perhaps more importantly, his obsessive attitudes were required to generate the resilience to bring the business side of this affair to a happy ...

... Eddington had a thorough understanding of the theory itself, as required to design the observations putting Einstein on the real axis of empirical reality. Perhaps more importantly, his obsessive attitudes were required to generate the resilience to bring the business side of this affair to a happy ...