Article
Physics, Multidisciplinary
Jean-Paul Blaizot, Jan M. Pawlowski, Urko Reinosa
Summary: This study combines two non-perturbative approaches, the 2PI action and fRG, to develop new approximations for strongly coupled systems. By exploiting exact 2PI relations, the infinite hierarchy of fRG equations is truncated with two exact conditions. This transformation offers new ways to solve the equations practically and provides insights on renormalization, potentially leading to new approximation schemes and truncation schemes beyond existing methods.
Article
Physics, Particles & Fields
P. V. Akacevich, A. V. Ivanov
Summary: In this paper, the two-loop contribution to the effective action of a two-dimensional non-linear sigma model is studied. A new formula, applicable to a regularization of general type, is derived. Known results for dimensional regularization are obtained as examples, and new types of cutoff are investigated. Non-local contributions and restrictions on the regularization are also discussed.
EUROPEAN PHYSICAL JOURNAL C
(2023)
Article
Physics, Multidisciplinary
Peter Millington, Paul M. Saffin
Summary: By exploiting the convexity of the two-particle-irreducible effective action, this study presents a procedure for extracting n-point vertex functions in zero-dimensional and higher-dimensional "quantum field theory". These findings extend the practicability and utility of an alternative approach to the functional renormalization group programme, and provide clarification on the relationship between flow equations for coupling parameters and vertices.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2022)
Article
Astronomy & Astrophysics
Guilherme H. S. Camargo, Ilya L. Shapiro
Summary: This paper reexamines the conformal anomaly in curved spacetime with antisymmetric torsion, and presents a covariant solution of the anomaly-induced effective action. The solution includes both local terms corresponding to derivatives in the conformal anomaly, and a nonlocal part free of ambiguities with a low-energy limit similar to the effective potential in the metric-scalar theory.
Article
Astronomy & Astrophysics
Holger Gies, Dimitrios Gkiatas, Luca Zambelli
Summary: In this paper, we combine a construction of BRST-invariant, nonlinear massive gauge fixing with the background field formalism. The resulting functional preserves the background-field invariance and BRST invariance of the quantum field. We verify the theory by computing the one-loop effective action and the beta function of the gauge coupling. We also study off-shell one-loop contributions and the application of the decoupling solution.
Article
Astronomy & Astrophysics
Stefan Floerchinger, Eduardo Grossi
Summary: The article discusses how the quantum effective action encodes Noether currents at the full quantum level. It also explores extended transformations and the corresponding nonconserved Noether currents. The paper focuses on symmetries and extended transformations associated with space-time geometry and presents a new divergence-type equation of motion for the shear current.
Article
Physics, Multidisciplinary
Dimitrios Bachtis, Gert Aarts, Francesco Di Renzo, Biagio Lucini
Summary: In this paper, we propose a method of inverse renormalization group transformations within the context of quantum field theory. This method can produce the appropriate critical fixed point structure, avoid the critical slowing down effect, and extract critical exponents. We also discuss the general applicability of this method and its insights into the structure of the renormalization group.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Particles & Fields
Stefano Di Noi, Luca Silvestrini
Summary: RGESolver is an open-source C++ library that performs leading-order evolution of dimension-six operators in the most general flavour scenario (assuming lepton and baryon number conservation) in the Standard Model Effective Theory. Due to its efficiency, RGESolver can be used for extensive phenomenological analyses within the framework of the Standard Model Effective Theory, incorporating the effects of renormalization group evolution.
EUROPEAN PHYSICAL JOURNAL C
(2023)
Article
Physics, Mathematical
Zhanjinag Ji
Summary: This paper introduces the concepts of G-Lipschitz tracking property, G-asymptotic average tracking property, and G-periodic tracking property, and studies their dynamical properties and topological structure. By analyzing compact metric G-spaces, several conclusions are drawn, which fill the gap in the theory of G-Lipschitz tracking property, G-asymptotic average tracking property, and G-periodic tracking property in infinite product space under group action.
ADVANCES IN MATHEMATICAL PHYSICS
(2022)
Article
Physics, Particles & Fields
A. Ivanov, N. Kharuk
Summary: In this paper, we investigate the two-loop contribution to the effective action of the four-dimensional quantum Yang-Mills theory. We derive a new formula for this contribution and test its consistency with results from other works using dimensional regularization and cutoff regularization.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Physics, Particles & Fields
Aneesh Manohar, Emily Nardoni
Summary: In this study, effective field theory (EFT) methods were used to compute the renormalization group improved effective potential for theories with a large mass hierarchy. The method allowed for systematic expansion in powers of mass ratio and summation of large logarithms of mass ratios using renormalization group evolution. The comparison of effective potentials computed using EFT and the effective potential of EFT was explained, and the method did not have a Goldstone boson infrared divergence problem.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Multidisciplinary
Han Ma, Sung-Sik Lee
Summary: In this paper, the Wilsonian effective action is presented as a solution to the exact RG equation for the critical O(N) vector model in the large N limit. The mapping between UV operators and IR scaling operators is obtained from the exact solution that describes the RG flow from a UV theory to the fixed point theory in the IR.
Article
Physics, Multidisciplinary
Takeru Yokota, Haruki Kasuya, Kenichi Yoshida, Teiji Kunihiro
Summary: A density-functional theory for superfluid systems is developed within the framework of the functional renormalization group, introducing the effective action for particle-number and non-local pairing densities. The resulting Kohn-Sham potential includes pairing potentials and expresses external, Hartree, pairing, and exchange-correlation terms separately. This formalism provides a systematic way to improve correlations and accurately predicts the ground-state energy of the Hartree-Fock-Bogoliubov theory.
PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS
(2021)
Article
Astronomy & Astrophysics
Mikael Chala, Arsenii Titov
Summary: In this study, the leading-logarithmic correction to the neutrino mass matrix in the Standard Model effective field theory was computed up to dimension seven, revealing the impact of dimension-seven operators on neutrino masses and the modifications introduced by dimension-six operators around the TeV scale. The findings are significant for the renormalization of the SMEFT.
Article
Astronomy & Astrophysics
Mariana Carrillo Gonzalez, Qiuyue Liang, Mark Trodden
Summary: The study extends the EFT formalism to gravitational radiation from a binary system of extended objects, particularly focusing on two infinitely-long cosmic strings. New perturbative expansion parameters are introduced to address the complexity of the system, with new power counting rules assigned. By integrating out modes corresponding to potential gravitons, an effective action for radiation gravitons is obtained, which describes a changing quadrupole caused by bending modes of the string generating gravitational waves. Ultraviolet divergences are studied to derive the classical renormalization group flow of the string tension in this setting.
Article
Physics, Multidisciplinary
G. Mustafa, S. K. Maurya, Saibal Ray, Faisal Javed
Summary: In this study, we investigate the geometry of wormholes in the framework of general relativity and explore how quantum wave dark matter affects the dynamical configuration of the shell surrounding the wormhole. By using specific shape functions and introducing quantum wave dark matter, we obtain reasonable wormhole solutions and observe its effects on the stability of the shell.
Article
Physics, Multidisciplinary
Pritha Dolai, Christian Maes
Summary: Calorimetry for equilibrium systems aims to determine the energy levels' occupation and distribution by measuring thermal response, while nonequilibrium versions provide additional information on the dynamical accessibility of these states. Using calculations on a driven exclusion process, it is confirmed that a fermionic nonequilibrium steady state with exact computation of specific heat can be achieved. The divergence at zero temperature occurs when the Fermi energy and the kinetic barrier for loading and emptying are approximately equal. Additionally, a stable low temperature regime of negative specific heat appears when the kinetic barrier is density-dependent, indicating an anti-correlation between the stationary occupation's temperature-dependence and excess heat.
Article
Physics, Multidisciplinary
F. F. Nascimento, V. B. Bezerra, J. M. Toledo
Summary: We obtained the metric of the Hayward black hole surrounded by a cloud of strings, and analyzed the effects of the string cloud on the regularity of the solution and the energy conditions. Various aspects such as horizons, geodesics, effective potential, and thermodynamics were investigated. We compared the obtained results with the literature corresponding to the Hayward black hole without a string cloud.
