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Related papers: Flow Equations without Mean Field Ambiguity

200 papers

A renormalization group flow equation with a scale-dependent transformation of field variables gives a unified description of fundamental and composite degrees of freedom. In the context of the effective average action, we study the…

High Energy Physics - Theory · Physics 2009-11-07 Holger Gies , Christof Wetterich

We develop a pairing mean-field theory to describe the quantum dynamics of the dissociation of molecular Bose-Einstein condensates into their constituent bosonic or fermionic atoms. We apply the theory to one, two, and three-dimensional…

Other Condensed Matter · Physics 2010-11-09 M. J. Davis , S. J. Thwaite , M. K. Olsen , K. V. Kheruntsyan

We review the formalism of the effective average action in quantum field theory which corresponds to a coarse grained free energy in statistical mechanics. The associated exact renormalization group equation and possible nonperturbative…

High Energy Physics - Phenomenology · Physics 2007-05-23 D. -U. Jungnickel , C. Wetterich

In the theory of hydrodynamic stability, the procedure to decompose an incompressible flow field into its basic motion and disturbances is imprecise and problematic because the disturbances, infinitesimal or finite, are ill-defined…

Fluid Dynamics · Physics 2018-12-13 F. Lam

By means of the continuous unitary transformation similar to a general scheme of the Renormalization Group (RG) procedure we study the issue of symmetry breaking and pairing instability in the system of interacting fermions. Constructing a…

Superconductivity · Physics 2009-11-11 T. Domanski , A. Donabidowicz

We formulate a generalized mean-field theory of a mixture of fermionic and bosonic atoms, in which the fermion-boson interaction can be controlled by a Feshbach resonance. The theory correctly accounts for molecular binding energies of the…

Other Condensed Matter · Physics 2009-11-13 D. C. E. Bortolotti , A. V. Avdeenkov , J. L. Bohn

We reveal the critical properties of the phase transition towards superfluid order that has been proposed to occur in large spin fermionic systems. For this purpose, we consider the bosonic field theory for fluctuations of the complex…

Statistical Mechanics · Physics 2023-05-03 Michal Hnatič , Georgii Kalagov

We discuss the application of normalizing flows to bosonic lattice field theories with real-time sign problems. A normalizing flow, once it is found for such a lattice field theory, is guaranteed to solve its sign problem. We argue for the…

High Energy Physics - Lattice · Physics 2022-01-03 Yukari Yamauchi , Scott Lawrence

We apply the flow equation method for studying the fermion systems where pairing interactions can either trigger the BCS instability with the symmetry breaking manifested by the off-diagonal order parameter or lead to the gaped single…

Superconductivity · Physics 2008-09-26 T. Domanski

Functional renormalisation group approach is applied to a imbalanced many- fermion system with a short-range attractive force. Composite boson field is introduced to describe the pairing between different flavour fermions. A set of…

Quantum Gases · Physics 2015-06-22 Boris Krippa

First-order phase transitions in many-fermion systems are not detected in the susceptibility analysis of common renormalization-group (RG) approaches. Here we introduce a counterterm technique within the functional renormalization-group…

Strongly Correlated Electrons · Physics 2007-05-23 R. Gersch , J. Reiss , C. Honerkamp

Mean-field games (MFGs) are a modeling framework for systems with a large number of interacting agents. They have applications in economics, finance, and game theory. Normalizing flows (NFs) are a family of deep generative models that…

Optimization and Control · Mathematics 2023-05-24 Han Huang , Jiajia Yu , Jie Chen , Rongjie Lai

Fermionic gradient flow in combination with the short-flow-time expansion provides a computational method where the renormalisation of hadronic matrix elements on the lattice can be simplified to address e.g. the issue that operators with…

High Energy Physics - Lattice · Physics 2024-12-02 Matthew Black , Robert Harlander , Fabian Lange , Antonio Rago , Andrea Shindler , Oliver Witzel

In physics one attempts to infer the rules governing a system given only the results of imperfect measurements. Hence, microscopic theories may be effectively indistinguishable experimentally. We develop an operationally motivated procedure…

Quantum Physics · Physics 2015-08-07 Cédric Bény , Tobias J. Osborne

We generalize the application of the functional renormalization group (fRG) method for the fermionic flow into the symmetry-broken phase to finite temperatures. We apply the scheme to the case of a broken discrete symmetry: the…

Strongly Correlated Electrons · Physics 2009-09-29 Roland Gersch , Carsten Honerkamp , Daniel Rohe , Walter Metzner

Fermionic functional renormalization group (FRG) is applied to describe the superfluid phase transition of the two-component fermionic system with attractive contact interaction. Connection between the fermionic FRG approach and the…

Quantum Gases · Physics 2014-08-19 Yuya Tanizaki , Gergely Fejős , Tetsuo Hatsuda

Some recent studies of the AdS/CFT correspondence for condensed matter systems involve the Fermi liquid theory as a boundary field theory. Adding B-flux to the boundary D-branes leads in a certain limit to the noncommutative Fermi liquid,…

High Energy Physics - Theory · Physics 2011-06-24 Sendic Estrada-Jimenez , Hugo Garcia-Compean , Yong-Shi Wu

The phase transition to superfluidity and the BCS-BEC crossover for an ultracold gas of fermionic atoms is discussed within a functional renormalization group approach. Non-perturbative flow equations, based on an exact renormalization…

Quantum Gases · Physics 2015-03-13 S. Diehl , S. Floerchinger , H. Gies , J. M. Pawlowski , C. Wetterich

We derive a theory of superfluidity for a dilute Fermi gas that is valid when scattering resonances are present. The treatment of a resonance in many-body atomic physics requires a novel mean-field approach starting from an unconventional…

Soft Condensed Matter · Physics 2009-11-07 S. J. J. M. F. Kokkelmans , J. N. Milstein , M. L. Chiofalo , R. Walser , M. J. Holland

We discuss the following proposition: Renormalization Group flow of quantum theory with a biased symmetry exhibits a fixed hypersurface at which the symmetry is exact. Such emergent symmetries may have important phenomenological…

High Energy Physics - Theory · Physics 2024-06-21 Zurab Berezhiani , Maicol Di Giambattista , Alessio Maiezza , Archil Kobakhidze