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Related papers: Dynamical overlap fermions with increased topologi…

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We compute fermionic observables relevant to the study of chiral symmetry in quenched QCD using the Overlap-Dirac operator for a wide range of the fermion mass. We use analytical results to disentangle the contribution from exact zero modes…

High Energy Physics - Lattice · Physics 2009-10-31 Robert G. Edwards , Urs M. Heller , Rajamani Narayanan

This paper reviews the most popular methods which are used in lattice QCD to compute the determinant of the lattice Dirac operator: Gaussian integral representation and noisy methods. Both of them lead naturally to matrix function problems.…

High Energy Physics - Lattice · Physics 2007-05-23 Artan Borici

Combining strong electron correlations [1-4] and nontrivial electronic topology [5] holds great promise for discovery. So far, this regime has been rarely accessed and systematic studies are much needed to advance the field. Here we…

The overlap fermion propagator is calculated on 2+1 flavor domain wall fermion gauge configurations on 16^3 x 32, 24^3 x 64 and 32^3 x 64 lattices. With HYP smearing and low eigenmode deflation, it is shown that the inversion of the overlap…

High Energy Physics - Lattice · Physics 2010-12-23 A. Li , A. Alexandru , Y. Chen , T. Doi , S. J. Dong , T. Draper , M. Gong , A. Hasenfratz , I. Horvath , F. X. Lee , K. F. Liu , N. Mathur , T. Streuer , J. B. Zhang

The correlations in charge transport in multiple Majorana fermions systems contain much richer physics and carry more information than the conventional transport coefficients. We calculate the auto- and cross-correlations in the spinful…

Strongly Correlated Electrons · Physics 2018-12-05 Oleksiy Kashuba

The dual-fermion approach provides a formally exact prescription for calculating properties of a correlated electron system in terms of a diagrammatic expansion around dynamical mean-field theory (DMFT). Most practical implementations,…

Strongly Correlated Electrons · Physics 2017-08-02 Jan Gukelberger , Evgeny Kozik , Hartmut Hafermann

We propose using Normalizing Flows as a trainable kernel within the molecular dynamics update of Hamiltonian Monte Carlo (HMC). By learning (invertible) transformations that simplify our dynamics, we can outperform traditional methods at…

Machine Learning · Computer Science 2021-12-06 Sam Foreman , Taku Izubuchi , Luchang Jin , Xiao-Yong Jin , James C. Osborn , Akio Tomiya

Two cluster algorithms, based on constructing and flipping loops, are presented for worldline quantum Monte Carlo simulations of fermions and are tested on the one-dimensional repulsive Hubbard model. We call these algorithms the loop-flip…

Condensed Matter · Physics 2007-05-23 N. Kawashima , J. E. Gubernatis , H. G. Evertz

For dense Hermitian matrices with small off-diagonal (numerical) ranks and in a hierarchically semiseparable form, we give a stable divide-and-conquer eigendecomposition method with nearly linear complexity (called SuperDC) that…

Numerical Analysis · Mathematics 2021-08-10 Xiaofeng Ou , Jianlin Xia

I describe an implementation of the overlap action, which is built from an action which is itself an approximate overlap action. It appears to be about a factor of 15-20 less expensive to use, than the usual overlap action with the Wilson…

High Energy Physics - Lattice · Physics 2008-11-26 Thomas DeGrand

The action of the overlap-Dirac operator on a vector is typically implemented indirectly through a multi-shift conjugate gradient solver. The compute-time required depends upon the condition number, $\kappa$, of the matrix that is used as…

High Energy Physics - Lattice · Physics 2010-03-04 W. Kamleh , D. B. Leinweber , A. G. Williams , J. B. Zhang

I solve a quantum chain whose Hamiltonian is comprised solely of local four-fermi operators by constructing free-fermion raising and lowering operators. The free-fermion operators are both non-local and highly non-linear in the local…

Statistical Mechanics · Physics 2019-11-06 Paul Fendley

Three aspects of symmetry structure of lattice chiral fermion in the overlap formalism are discussed. By the weak coupling expansion of the overlap Dirac operator, the axial anomaly associated to the chiral transformation proposed by…

High Energy Physics - Lattice · Physics 2009-10-31 Y. Kikukawa

The past few years have seen considerable progress in algorithmic development for the generation of gauge fields including the effects of dynamical fermions. The Rational Hybrid Monte Carlo (RHMC) algorithm, where Hybrid Monte Carlo is…

High Energy Physics - Lattice · Physics 2008-11-26 M. A. Clark

We study the super and dynamical symmetries of a fermion in a monopole background. The Hamiltonian also involves an additional spin-orbit coupling term, which is parameterized by the gyromagnetic ratio. We construct the superinvariants…

High Energy Physics - Theory · Physics 2015-05-18 J. -P. Ngome , P. A. Horváthy , J. W. van Holten

In order to construct improved overlap fermions, we start from a short ranged approximate Ginsparg-Wilson fermion and insert it into the overlap formula. We show that its polynomial evaluation is accelerated considerably compared to the…

High Energy Physics - Lattice · Physics 2015-06-25 W. Bietenholz , I. Hip , K. Schilling

A new diagrammatic technique is developed to describe nonlocal effects (e.g., pseudogap formation) in the Hubbard-like models. In contrast to cluster approaches, this method utilizes an exact transition to the dual set of variables, and it…

Strongly Correlated Electrons · Physics 2007-05-23 A. N. Rubtsov , M. I. Katsnelson , A. I. Lichtenstein

A transformation is devised to convert any lattice Dirac fermion operator into a Ginsparg-Wilson Dirac fermion operator. For the standard Wilson-Dirac lattice fermion operator, the transformed new operator is local, free of O(a) lattice…

High Energy Physics - Lattice · Physics 2011-02-16 Ting-Wai Chiu

In the simplified setting of the Schwinger model we present a systematic study on the simulation of dynamical fermions by global accept/reject steps that take into account the fermion determinant. A family of exact algorithms is developed,…

High Energy Physics - Lattice · Physics 2008-11-26 Francesco Knechtli , Ulli Wolff

We introduce a new algorithm which we call the {Rational Hybrid Monte Carlo} Algorithm (RHMC). This method uses a rational approximation to the fermionic kernel together with a noisy Kennedy-Kuti acceptance step to give an efficient…

High Energy Physics - Lattice · Physics 2009-10-31 Ivan Horvath , A. D. Kennedy , Stefan Sint
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