Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Sparse modeling of large-scale quantum impurity models with low
  symmetries   Quantum embedding theories provide a feasible route for obtaining
quantitative descriptions of correlated materials. However, a critical
challenge is solving an effective impurity model of correlated orbitals
embedded in an electron bath. Many advanced impurity solvers require the
approximation of a bath continuum using a finite number of bath levels,
producing a highly nonconvex, ill-conditioned inverse problem. To address this
drawback, this study proposes an efficient fitting algorithm for matrix-valued
hybridization functions based on a data-science approach, sparse modeling, and
a compact representation of Matsubara Green's functions. The efficiency of the
proposed method is demonstrated by fitting random hybridization functions with
large off-diagonal elements as well as those of a 20-orbital impurity model for
a high-Tc compound, LaAsFeO, at low temperatures (T). The results set
quantitative goals for the future development of impurity solvers toward
quantum embedding simulations of complex correlated materials.

9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin
25
The categories of this paper are: patt-sol
35
The categories of this paper are: mtrl-th
5
The categories of this paper are: gr-qc
19
The categories of this paper are: eess
37
The categories of this paper are: supr-con
24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
6
The categories of this paper are: astro-ph