Contextual extensions of quantum gravity models
نویسندگان
چکیده
We present a simple way of incorporating the structure contextual extensions into quantum gravity models. The [Formula: see text]-algebras, originally proposed for hidden variables, are generalized to cones indexed by contexts and their limit in category. By abstracting models as functors, we study categorical limits these functors several Such useful building topos-theoretic gravity.
منابع مشابه
Reduced models for quantum gravity
As outlined in various other lectures given at this meeting, it seems that a quantum theory of gravity can only be constructed in a non perturbative manner (compare, in particular, Ashtekar’s lectures). Because of that, no calculations, as for example cross sections, decay rates and so on, can be done for the full theory of 3+1 gravity unless one has the full solution space of the quantum const...
متن کاملExtensions of 2d Gravity * †
Conformally invariant theories in two dimensions play an important role in the study of string theories, second order phase transitions and integrable systems. The Virasoro algebra and its extensions form the cornerstone of conformal field theories. More recently a lot of attention was devoted to the study of a particular class of conformal field theories: gravity in two dimensions. As I will s...
متن کاملSpin Foam Models of Quantum Gravity
We give a short review of the spin foam models of quantum gravity , with an emphasis on the Barret-Crane model. After explaining the shortcomings of the Barret-Crane model, we briefly discuss two new approaches , one based on the 3d spin foam state sum invariants for the embedded spin networks, and the other based on representing the string scattering amplitudes as 2d spin foam state sum invari...
متن کاملPhenomenology of Low Quantum Gravity Scale Models
We study some phenomenological implications of models where the scale of quantum gravity effects lies much below the four-dimensional Planck scale. These models arise from M-theory vacua where either the internal space volume is large or the string coupling is very small. We provide a critical analysis of ways to unify electroweak, strong and gravitational interactions in M-theory. We discuss t...
متن کاملMidi-superspace Models of Canonical Quantum Gravity *
A midi-superspace model is a field theory obtained by symmetry reduction of a parent gravitational theory. Such models have proven useful for exploring the classical and quantum dynamics of the gravitational field. I present 3 recent classes of results pertinent to canonical quantization of vacuum general relativity in the context of midi-superspace models. (1) I give necessary and sufficient c...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: International Journal of Geometric Methods in Modern Physics
سال: 2021
ISSN: ['0219-8878', '1793-6977']
DOI: https://doi.org/10.1142/s0219887821500857