English
Related papers

Related papers: In-medium similarity renormalization group with th…

200 papers

We have developed an {\it ab initio} deformed in-medium similarity renormalization group (IMSRG) for open-shell nuclei. This is a single-reference IMSRG in deformed Hartree-Fock (HF) basis. Deformed wave functions are more efficient in…

Nuclear Theory · Physics 2022-07-13 Q. Yuan , S. Q. Fan , B. S. Hu , J. G. Li , S. Zhang , S. M. Wang , Z. H. Sun , Y. Z. Ma , F. R. Xu

The study of nuclei at finite temperature is of immense interest for many areas of nuclear astrophysics and nuclear-reaction science. A variety of ab initio methods are now available for computing the properties of nuclei from interactions…

Nuclear Theory · Physics 2025-04-25 Isaac G. Smith , Heiko Hergert , Scott K. Bogner

This study examines several techniques to improve the efficiency of the linearized multireference driven similarity renormalization group truncated to one- and two-body operators [MR-LDSRG(2)]. We propose a sequential MR-LDSRG(2)…

Chemical Physics · Physics 2019-03-29 Tianyuan Zhang , Chenyang Li , Francesco A. Evangelista

A one-dimensional system of bosons with short-range repulsion and mid-range attraction is used as a laboratory to explore the evolution of many-body forces by the Similarity Renormalization Group (SRG). The free-space SRG is implemented for…

Nuclear Theory · Physics 2009-02-12 E. D. Jurgenson , R. J. Furnstahl

We present an improved variant of the in-medium similarity renormalization group (IM-SRG) based on the Magnus expansion. In the new formulation, one solves flow equations for the anti-hermitian operator that, upon exponentiation, yields the…

Nuclear Theory · Physics 2015-10-07 T. D. Morris , N. Parzuchowski , S. K. Bogner

The first nonperturbative version of the multireference driven similarity renormalization group (MR-DSRG) theory [C. Li and F. A. Evangelista, J. Chem. Theory Comput. $\mathbf{11}$, 2097 (2015)] is introduced. The renormalization group…

Chemical Physics · Physics 2016-05-25 Chenyang Li , Francesco A. Evangelista

The similarity renormalization group (SRG) has been successfully applied to soften interactions for ab initio nuclear calculations. In almost all practical applications in nuclear physics, an SRG generator with the kinetic energy operator…

Nuclear Theory · Physics 2014-09-10 Nuiok M. Dicaire , Conor Omand , Petr Navratil

We formulate the In-Medium Similarity Renormalization Group (IM-SRG) for open-shell nuclei using a multi-reference formalism based on a generalized Wick theorem introduced in quantum chemistry. The resulting multi-reference IM-SRG…

Nuclear Theory · Physics 2013-06-13 H. Hergert , S. Binder , A. Calci , J. Langhammer , R. Roth

We summarize our recent efforts to develop the Density Matrix Renormalization Group (DMRG) method into a practical truncation strategy for large-scale nuclear shell model calculations. Following an overview of the essential features of the…

Nuclear Theory · Physics 2009-04-16 S. Pittel , B. Thakur

We merge two successful ab initio nuclear-structure methods, the no-core shell model (NCSM) and the multi-reference in-medium similarity renormalization group (IM-SRG) to define a new many-body approach for the comprehensive description of…

Nuclear Theory · Physics 2017-04-20 Eskendr Gebrerufael , Klaus Vobig , Heiko Hergert , Robert Roth

The computational cost of ab initio nuclear structure calculations is rendered particularly acute by the presence of (at least) three-nucleon interactions. This feature becomes especially critical now that many-body methods aim at extending…

We report on recent progress of the implementation of the similarity renormalization group (SRG) for three-body interactions in a one-dimensional, bosonic model system using the plane wave basis. We discuss our implementation of the flow…

Nuclear Theory · Physics 2013-04-12 O. Åkerlund , E. J. Lindgren , J. Bergsten , B. Grevholm , P. Lerner , R. Linscott , C. Forssén , L. Platter

We propose a novel many-body framework combining the density matrix renormalization group (DMRG) with the valence-space (VS) formulation of the in-medium similarity renormalization group. This hybrid scheme admits for favorable…

Nuclear Theory · Physics 2023-09-12 A. Tichai , S. Knecht , A. T. Kruppa , Ö. Legeza , C. P. Moca , A. Schwenk , M. A. Werner , G. Zarand

We develop a framework that allows to calculate integrated properties of the nuclear response from first principles. Using the ab initio in-medium similarity renormalization group (IMSRG), we calculate the expectation values of moment…

Nuclear Theory · Physics 2025-11-10 Andrea Porro , Achim Schwenk , Alexander Tichai

In this work, we combine the many-body formulation of the internally contracted multireference coupled cluster (ic-MRCC) method with Evangelista's multireference formulation of the driven similarity renormalization group (DSRG). The DSRG…

Chemical Physics · Physics 2025-03-04 Robin Feldmann , Markus Reiher

We investigate the Ising and Heisenberg models using the Block Renormalization Group Method (BRGM), focusing on its behavior across different system sizes. The BRGM reduces the number of spins by a factor of 1/2 (1/3) for the Ising…

A new approach to large-scale nuclear structure calculations, based on the Density Matrix Renormalization Group (DMRG), is described. The method is tested in the context of a problem involving many identical nucleons constrained to move in…

Nuclear Theory · Physics 2011-05-12 J. Dukelsky , S. Pittel

We introduce a novel \abinitio many-body method designed to compute the properties of nuclei in the continuum. This approach combines well-established techniques, namely the Complex Scaling (CS) and Similarity Renormalization Group (SRG)…

Nuclear Theory · Physics 2025-07-03 Osama Yaghi , Guillaume Hupin , Petr Navrátil

In recent years, the Similarity Renormalization Group has provided a powerful and versatile means to soften interactions for ab initio nuclear calculations. The substantial contribution of both induced and initial three-body forces to the…

Nuclear Theory · Physics 2011-03-22 E. D. Jurgenson , P. Navratil , R. J. Furnstahl

The Similarity Renormalization Group (SRG) is used to soften interactions for ab initio nuclear structure calculations by decoupling low- and high-energy Hamiltonian matrix elements. The substantial contribution of both initial and…

Nuclear Theory · Physics 2013-05-22 E. D. Jurgenson , P. Maris , R. J. Furnstahl , P. Navratil , W. E. Ormand , J. P. Vary