scholarly journals How general relativity and Lorentz covariance arise from the spatially-covariant effective field theory of the transverse, traceless graviton

2014 ◽  
Vol 23 (12) ◽  
pp. 1442012 ◽  
Author(s):  
Justin Khoury ◽  
Godfrey E. J. Miller ◽  
Andrew J. Tolley

Traditional derivations of general relativity (GR) from the graviton degrees of freedom assume spacetime Lorentz covariance as an axiom. In this paper, we survey recent evidence that GR is the unique spatially-covariant effective field theory of the transverse, traceless graviton degrees of freedom. The Lorentz covariance of GR, having not been assumed in our analysis, is thus plausibly interpreted as an accidental or emergent symmetry of the gravitational sector. From this point of view, Lorentz covariance is a necessary feature of low-energy graviton dynamics, not a property of spacetime. This result has revolutionary implications for fundamental physics.

2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
Yi Liao ◽  
Xiao-Dong Ma ◽  
Quan-Yu Wang

Abstract We present a complete and independent set of dimension-7 operators in the low energy effective field theory (LEFT) where the dynamical degrees of freedom are the standard model five quarks and all of the neutral and charged leptons. All operators are non-Hermitian and are classified according to their baryon (∆B) and lepton (∆L) numbers violated. Including Hermitian-conjugated operators, there are in total 3168, 750, 588, 712 operators with (∆B, ∆L) = (0, 0), (0, ±2), (±1, ∓1), (±1, ±1) respectively. We perform the tree-level matching with the standard model effective field theory (SMEFT) up to dimension-7 (dim-7) operators in both LEFT and SMEFT. As a phenomenological application we study the effective neutrino-photon interactions due to dim-7 lepton number violating operators that are induced and much enhanced at one loop from dim-6 operators that in turn are matched from dim-7 SMEFT operators. We compare various neutrino-photon scattering cross sections with their counterparts in the standard model and highlight the new features. Finally, we illustrate how these effective interactions could arise from ultraviolet completion.


2021 ◽  
Vol 81 (2) ◽  
Author(s):  
Javier Fuentes-Martín ◽  
Pedro Ruiz-Femenía ◽  
Avelino Vicente ◽  
Javier Virto

Abstract is a package for the handling of the standard model effective field theory (SMEFT) and the low-energy effective field theory (LEFT) with operators up to dimension six, both at the algebraic and numerical level. contains a visually accessible and operationally convenient repository of all operators and parameters of the SMEFT and the LEFT. This repository also provides information concerning symmetry categories and number of degrees of freedom, and routines that allow to implement this information on global expressions (such as decay amplitudes and cross-sections). also performs weak basis transformations, and implements the full one-loop Renormalization Group Evolution in both EFTs (with SM beta functions up to five loops in QCD), and the full one-loop SMEFT-LEFT matching at the electroweak scale.


2016 ◽  
Vol 31 (06) ◽  
pp. 1630007 ◽  
Author(s):  
Steven Weinberg

I reminisce about the early development of effective field theories of the strong interactions, comment briefly on some other applications of effective field theories, and then take up the idea that the Standard Model and General Relativity are the leading terms in an effective field theory. Finally, I cite recent calculations that suggest that the effective field theory of gravitation and matter is asymptotically safe.


2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Tong Li ◽  
Xiao-Dong Ma ◽  
Michael A. Schmidt

Abstract In this work we investigate the implication of low-energy precision measurements on the quark-lepton charged currents in general neutrino interactions with sterile neutrinos in effective field theories. The physics in low-energy measurements is described by the low-energy effective field theory extended with sterile neutrinos (LNEFT) defined below the electroweak scale. We also take into account renormalization group running and match the LNEFT onto the Standard Model (SM) effective field theory with sterile neutrinos (SMNEFT) to constrain new physics (NP) above the electroweak scale. The most sensitive low-energy probes are from leptonic decays of pseudoscalar mesons and hadronic tau lepton decays in terms of precise decay branching fractions, the lepton flavor universality and the Cabibbo-Kobayashi-Maskawa (CKM) unitarity. We also consider other constraints including nuclear beta decay. The constraints on charged current operators are generally stronger than the ones for quark-neutrino neutral current operators. We find that the most stringent bounds on the NP scale of lepton-number-conserving and lepton- number-violating operators in SMNEFT are 74 (110) TeV and 9.8 (13) TeV, respectively, for the operators with down (strange) quark.


2014 ◽  
pp. 200-236
Author(s):  
John F. Donoghue ◽  
Eugene Golowich ◽  
Barry R. Holstein

2018 ◽  
Vol 175 ◽  
pp. 08011 ◽  
Author(s):  
Ed Bennett ◽  
Deog Ki Hong ◽  
Jong-Wan Lee ◽  
C.-J. David Lin ◽  
Biagio Lucini ◽  
...  

As a first step towards a quantitative understanding of the SU(4)/Sp(4) composite Higgs model through lattice calculations, we discuss the low energy effective field theory resulting from the SU(4) → Sp(4) global symmetry breaking pattern. We then consider an Sp(4) gauge theory with two Dirac fermion flavours in the fundamental representation on a lattice, which provides a concrete example of the microscopic realisation of the SU(4)/Sp(4) composite Higgs model. For this system, we outline a programme of numerical simulations aiming at the determination of the low-energy constants of the effective field theory and we test the method on the quenched theory. We also report early results from dynamical simulations, focussing on the phase structure of the lattice theory and a calculation of the lowest-lying meson spectrum at coarse lattice spacing.


2009 ◽  
Vol 24 (11n13) ◽  
pp. 921-930
Author(s):  
HERMANN KREBS

Using chiral effective field theory (EFT) with explicit Δ degrees of freedom we calculated nuclear forces up to next-to-next-to-leading order (N2LO). We find a much improved convergence of the chiral expansion in all peripheral partial waves. We also present a novel lattice EFT method developed for systems with larger number of nucleons. Combining Monte Carlo lattice simulations with EFT allows one to calculate the properties of light nuclei, neutron and nuclear matter. Accurate description of two-nucleon phase-shifts and ground state energy ratio of dilute neutron matter up to corrections of higher orders show that lattice EFT is a promising tool for quantitative studies of low-energy few- and many-body systems.


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