---
_id: '721'
abstract:
- lang: eng
text: 'Let S be a positivity-preserving symmetric linear operator acting on bounded
functions. The nonlinear equation -1/m=z+Sm with a parameter z in the complex
upper half-plane ℍ has a unique solution m with values in ℍ. We show that the
z-dependence of this solution can be represented as the Stieltjes transforms of
a family of probability measures v on ℝ. Under suitable conditions on S, we show
that v has a real analytic density apart from finitely many algebraic singularities
of degree at most 3. Our motivation comes from large random matrices. The solution
m determines the density of eigenvalues of two prominent matrix ensembles: (i)
matrices with centered independent entries whose variances are given by S and
(ii) matrices with correlated entries with a translation-invariant correlation
structure. Our analysis shows that the limiting eigenvalue density has only square
root singularities or cubic root cusps; no other singularities occur.'
author:
- first_name: Oskari H
full_name: Ajanki, Oskari H
id: 36F2FB7E-F248-11E8-B48F-1D18A9856A87
last_name: Ajanki
- first_name: Torben H
full_name: Krüger, Torben H
id: 3020C786-F248-11E8-B48F-1D18A9856A87
last_name: Krüger
orcid: 0000-0002-4821-3297
- first_name: László
full_name: Erdös, László
id: 4DBD5372-F248-11E8-B48F-1D18A9856A87
last_name: Erdös
orcid: 0000-0001-5366-9603
citation:
ama: Ajanki OH, Krüger TH, Erdös L. Singularities of solutions to quadratic vector
equations on the complex upper half plane. Communications on Pure and Applied
Mathematics. 2017;70(9):1672-1705. doi:10.1002/cpa.21639
apa: Ajanki, O. H., Krüger, T. H., & Erdös, L. (2017). Singularities of solutions
to quadratic vector equations on the complex upper half plane. Communications
on Pure and Applied Mathematics. Wiley-Blackwell. https://doi.org/10.1002/cpa.21639
chicago: Ajanki, Oskari H, Torben H Krüger, and László Erdös. “Singularities of
Solutions to Quadratic Vector Equations on the Complex Upper Half Plane.” Communications
on Pure and Applied Mathematics. Wiley-Blackwell, 2017. https://doi.org/10.1002/cpa.21639.
ieee: O. H. Ajanki, T. H. Krüger, and L. Erdös, “Singularities of solutions to quadratic
vector equations on the complex upper half plane,” Communications on Pure and
Applied Mathematics, vol. 70, no. 9. Wiley-Blackwell, pp. 1672–1705, 2017.
ista: Ajanki OH, Krüger TH, Erdös L. 2017. Singularities of solutions to quadratic
vector equations on the complex upper half plane. Communications on Pure and Applied
Mathematics. 70(9), 1672–1705.
mla: Ajanki, Oskari H., et al. “Singularities of Solutions to Quadratic Vector Equations
on the Complex Upper Half Plane.” Communications on Pure and Applied Mathematics,
vol. 70, no. 9, Wiley-Blackwell, 2017, pp. 1672–705, doi:10.1002/cpa.21639.
short: O.H. Ajanki, T.H. Krüger, L. Erdös, Communications on Pure and Applied Mathematics
70 (2017) 1672–1705.
date_created: 2018-12-11T11:48:08Z
date_published: 2017-09-01T00:00:00Z
date_updated: 2021-01-12T08:12:24Z
day: '01'
department:
- _id: LaEr
doi: 10.1002/cpa.21639
ec_funded: 1
intvolume: ' 70'
issue: '9'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1512.03703
month: '09'
oa: 1
oa_version: Submitted Version
page: 1672 - 1705
project:
- _id: 258DCDE6-B435-11E9-9278-68D0E5697425
call_identifier: FP7
grant_number: '338804'
name: Random matrices, universality and disordered quantum systems
publication: Communications on Pure and Applied Mathematics
publication_identifier:
issn:
- '00103640'
publication_status: published
publisher: Wiley-Blackwell
publist_id: '6959'
quality_controlled: '1'
scopus_import: 1
status: public
title: Singularities of solutions to quadratic vector equations on the complex upper
half plane
type: journal_article
user_id: 4435EBFC-F248-11E8-B48F-1D18A9856A87
volume: 70
year: '2017'
...