The Experts below are selected from a list of 51 Experts worldwide ranked by ideXlab platform

Victor Gorbenko - One of the best experts on this subject based on the ideXlab platform.

  • solving the Simplest Theory of quantum gravity
    Journal of High Energy Physics, 2012
    Co-Authors: Sergei Dubovsky, Raphael Flauger, Victor Gorbenko
    Abstract:

    We solve what is quite likely the Simplest model of quantum gravity, the worldsheet Theory of an infinitely long, free bosonic string in Minkowski space. Contrary to naive expectations, this Theory is non-trivial. We illustrate this by constructing its exact factorizable S-matrix. Despite its simplicity, the Theory exhibits many of the salient features expected from more mature quantum gravity models, including the absence of local off-shell observables, a minimal length, as well as (integrable relatives of) black holes. All these properties follow from the exact S-matrix. We show that the complete finite volume spectrum can be reconstructed analytically from this S-matrix with the help of the thermodynamic Bethe Ansatz. We argue that considered as a UV complete relativistic 2-dimensional quantum field Theory the model exhibits a new type of renormalization group flow behavior, “asymptotic fragility”. Asymptotically fragile flows do not originate from a UV fixed point.

  • solving the Simplest Theory of quantum gravity
    arXiv: High Energy Physics - Theory, 2012
    Co-Authors: Sergei Dubovsky, Raphael Flauger, Victor Gorbenko
    Abstract:

    We solve what is quite likely the Simplest model of quantum gravity, the worldsheet Theory of an infinitely long, free bosonic string in Minkowski space. Contrary to naive expectations, this Theory is non-trivial. We illustrate this by constructing its exact factorizable S-matrix. Despite its simplicity, the Theory exhibits many of the salient features expected from more mature quantum gravity models, including the absence of local off-shell observables, a minimal length, a maximum achievable (Hagedorn) temperature, as well as (integrable relatives of) black holes. All these properties follow from the exact S-matrix. We show that the complete finite volume spectrum can be reconstructed analytically from this S-matrix with the help of the thermodynamic Bethe Ansatz. We argue that considered as a UV complete relativistic two-dimensional quantum field Theory the model exhibits a new type of renormalization group flow behavior, "asymptotic fragility". Asymptotically fragile flows do not originate from a UV fixed point.

Damiano Anselmi - One of the best experts on this subject based on the ideXlab platform.

  • on the quantum field Theory of the gravitational interactions
    Journal of High Energy Physics, 2017
    Co-Authors: Damiano Anselmi
    Abstract:

    We study the main options for a unitary and renormalizable, local quantum field Theory of the gravitational interactions. The first model is a Lee-Wick superrenormalizable higher-derivative gravity, formulated as a nonanalytically Wick rotated Euclidean Theory. We show that, under certain conditions, the $S$ matrix is unitary when the cosmological constant vanishes. The model is the Simplest of its class. However, infinitely many similar options are allowed, which raises the issue of uniqueness. To deal with this problem, we propose a new quantization prescription, by doubling the unphysical poles of the higher-derivative propagators and turning them into Lee-Wick poles. The Lagrangian of the Simplest Theory of quantum gravity based on this idea is the linear combination of $R$, $R_{\mu \nu}R^{\mu \nu }$, $R^{2}$ and the cosmological term. Only the graviton propagates in the cutting equations and, when the cosmological constant vanishes, the $S$ matrix is unitary. The Theory satisfies the locality of counterterms and is renormalizable by power counting. It is unique in the sense that it is the only one with a dimensionless gauge coupling.

Sergei Dubovsky - One of the best experts on this subject based on the ideXlab platform.

  • solving the Simplest Theory of quantum gravity
    Journal of High Energy Physics, 2012
    Co-Authors: Sergei Dubovsky, Raphael Flauger, Victor Gorbenko
    Abstract:

    We solve what is quite likely the Simplest model of quantum gravity, the worldsheet Theory of an infinitely long, free bosonic string in Minkowski space. Contrary to naive expectations, this Theory is non-trivial. We illustrate this by constructing its exact factorizable S-matrix. Despite its simplicity, the Theory exhibits many of the salient features expected from more mature quantum gravity models, including the absence of local off-shell observables, a minimal length, as well as (integrable relatives of) black holes. All these properties follow from the exact S-matrix. We show that the complete finite volume spectrum can be reconstructed analytically from this S-matrix with the help of the thermodynamic Bethe Ansatz. We argue that considered as a UV complete relativistic 2-dimensional quantum field Theory the model exhibits a new type of renormalization group flow behavior, “asymptotic fragility”. Asymptotically fragile flows do not originate from a UV fixed point.

  • solving the Simplest Theory of quantum gravity
    arXiv: High Energy Physics - Theory, 2012
    Co-Authors: Sergei Dubovsky, Raphael Flauger, Victor Gorbenko
    Abstract:

    We solve what is quite likely the Simplest model of quantum gravity, the worldsheet Theory of an infinitely long, free bosonic string in Minkowski space. Contrary to naive expectations, this Theory is non-trivial. We illustrate this by constructing its exact factorizable S-matrix. Despite its simplicity, the Theory exhibits many of the salient features expected from more mature quantum gravity models, including the absence of local off-shell observables, a minimal length, a maximum achievable (Hagedorn) temperature, as well as (integrable relatives of) black holes. All these properties follow from the exact S-matrix. We show that the complete finite volume spectrum can be reconstructed analytically from this S-matrix with the help of the thermodynamic Bethe Ansatz. We argue that considered as a UV complete relativistic two-dimensional quantum field Theory the model exhibits a new type of renormalization group flow behavior, "asymptotic fragility". Asymptotically fragile flows do not originate from a UV fixed point.

Alexander Rand - One of the best experts on this subject based on the ideXlab platform.

  • average interpolation under the maximum angle condition
    SIAM Journal on Numerical Analysis, 2012
    Co-Authors: Alexander Rand
    Abstract:

    Interpolation error estimates needed in common finite element applications using simplicial meshes typically impose restrictions on both the smoothness of the interpolated functions and the shape of the simplices. While the Simplest Theory can be generalized to admit less smooth functions (e.g., functions in $H^1(\Omega)$ rather than $H^2(\Omega)$) and more general shapes (e.g., the maximum angle condition rather than the minimum angle condition), existing Theory does not allow these extensions to be performed simultaneously. By localizing over a well-shaped auxiliary spatial partition, error estimates are established under minimal function smoothness and mesh regularity. This construction is especially important in two cases: $L^p(\Omega)$ estimates for data in $W^{1,p}(\Omega)$ hold for meshes without any restrictions on simplex shape, and $W^{1,p}(\Omega)$ estimates for data in $W^{2,p}(\Omega)$ hold under a generalization of the maximum angle condition which requires $p>2$ for standard Lagrange interp...

  • average interpolation under the maximum angle condition
    arXiv: Numerical Analysis, 2011
    Co-Authors: Alexander Rand
    Abstract:

    Interpolation error estimates needed in common finite element applications using simplicial meshes typically impose restrictions on the both the smoothness of the interpolated functions and the shape of the simplices. While the Simplest Theory can be generalized to admit less smooth functions (e.g., functions in H^1(\Omega) rather than H^2(\Omega)) and more general shapes (e.g., the maximum angle condition rather than the minimum angle condition), existing Theory does not allow these extensions to be performed simultaneously. By localizing over a well-shaped auxiliary spatial partition, error estimates are established under minimal function smoothness and mesh regularity. This construction is especially important in two cases: L^p(\Omega) estimates for data in W^{1,p}(\Omega) hold for meshes without any restrictions on simplex shape, and W^{1,p}(\Omega) estimates for data in W^{2,p}(\Omega) hold under a generalization of the maximum angle condition which previously required p>2 for standard Lagrange interpolation.

Raphael Flauger - One of the best experts on this subject based on the ideXlab platform.

  • solving the Simplest Theory of quantum gravity
    Journal of High Energy Physics, 2012
    Co-Authors: Sergei Dubovsky, Raphael Flauger, Victor Gorbenko
    Abstract:

    We solve what is quite likely the Simplest model of quantum gravity, the worldsheet Theory of an infinitely long, free bosonic string in Minkowski space. Contrary to naive expectations, this Theory is non-trivial. We illustrate this by constructing its exact factorizable S-matrix. Despite its simplicity, the Theory exhibits many of the salient features expected from more mature quantum gravity models, including the absence of local off-shell observables, a minimal length, as well as (integrable relatives of) black holes. All these properties follow from the exact S-matrix. We show that the complete finite volume spectrum can be reconstructed analytically from this S-matrix with the help of the thermodynamic Bethe Ansatz. We argue that considered as a UV complete relativistic 2-dimensional quantum field Theory the model exhibits a new type of renormalization group flow behavior, “asymptotic fragility”. Asymptotically fragile flows do not originate from a UV fixed point.

  • solving the Simplest Theory of quantum gravity
    arXiv: High Energy Physics - Theory, 2012
    Co-Authors: Sergei Dubovsky, Raphael Flauger, Victor Gorbenko
    Abstract:

    We solve what is quite likely the Simplest model of quantum gravity, the worldsheet Theory of an infinitely long, free bosonic string in Minkowski space. Contrary to naive expectations, this Theory is non-trivial. We illustrate this by constructing its exact factorizable S-matrix. Despite its simplicity, the Theory exhibits many of the salient features expected from more mature quantum gravity models, including the absence of local off-shell observables, a minimal length, a maximum achievable (Hagedorn) temperature, as well as (integrable relatives of) black holes. All these properties follow from the exact S-matrix. We show that the complete finite volume spectrum can be reconstructed analytically from this S-matrix with the help of the thermodynamic Bethe Ansatz. We argue that considered as a UV complete relativistic two-dimensional quantum field Theory the model exhibits a new type of renormalization group flow behavior, "asymptotic fragility". Asymptotically fragile flows do not originate from a UV fixed point.