Spectral Analysis of Lattice Schrödinger-Type Operators Associated with the Nonstationary Anderson Model and Intermittency

We investigate the nonstationary parabolic Anderson problem <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mstyle scriptlevel="0" displaystyle="true"><mfrac><mrow>&l...

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Main Authors: Dan Han, Stanislav Molchanov, Boris Vainberg
Format: Article
Language:English
Published: MDPI AG 2025-02-01
Series:Mathematics
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Online Access:https://www.mdpi.com/2227-7390/13/5/685
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author Dan Han
Stanislav Molchanov
Boris Vainberg
author_facet Dan Han
Stanislav Molchanov
Boris Vainberg
author_sort Dan Han
collection DOAJ
description We investigate the nonstationary parabolic Anderson problem <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mstyle scriptlevel="0" displaystyle="true"><mfrac><mrow><mo>∂</mo><mi>u</mi></mrow><mrow><mo>∂</mo><mi>t</mi></mrow></mfrac></mstyle><mo>=</mo><mi>ϰ</mi><mi mathvariant="script">L</mi><mi>u</mi><mrow><mo stretchy="false">(</mo><mi>t</mi><mo>,</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><mo>+</mo><msub><mi>ξ</mi><mi>t</mi></msub><mrow><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><mi>u</mi><mrow><mo stretchy="false">(</mo><mi>t</mi><mo>,</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><mo>,</mo><mspace width="1.em"></mspace><mi>u</mi><mrow><mo stretchy="false">(</mo><mn>0</mn><mo>,</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><mo>≡</mo><mn>1</mn><mo>,</mo><mspace width="1.em"></mspace><mrow><mo stretchy="false">(</mo><mi>t</mi><mo>,</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><mo>∈</mo><mrow><mo>[</mo><mn>0</mn><mo>,</mo><mo>∞</mo><mo stretchy="false">)</mo></mrow><mo>×</mo><msup><mi>Z</mi><mi>d</mi></msup></mrow></semantics></math></inline-formula> where <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>ϰ</mi><mi mathvariant="script">L</mi></mrow></semantics></math></inline-formula> denotes a nonlocal Laplacian and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>ξ</mi><mi>t</mi></msub><mrow><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow></mrow></semantics></math></inline-formula> is a correlated white-noise potential. The irregularity of the solution is linked to the upper spectrum of certain multiparticle Schrödinger operators that govern the moment functions <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>m</mi><mi>p</mi></msub><mrow><mo stretchy="false">(</mo><mi>t</mi><mo>,</mo><msub><mi>x</mi><mn>1</mn></msub><mo>,</mo><msub><mi>x</mi><mn>2</mn></msub><mo>,</mo><mo>⋯</mo><mo>,</mo><msub><mi>x</mi><mi>p</mi></msub><mo stretchy="false">)</mo></mrow><mo>=</mo><mrow><mo>⟨</mo><mi>u</mi><mrow><mo stretchy="false">(</mo><mi>t</mi><mo>,</mo><msub><mi>x</mi><mn>1</mn></msub><mo stretchy="false">)</mo></mrow><mi>u</mi><mrow><mo stretchy="false">(</mo><mi>t</mi><mo>,</mo><msub><mi>x</mi><mn>2</mn></msub><mo stretchy="false">)</mo></mrow><mo>⋯</mo><mi>u</mi><mrow><mo stretchy="false">(</mo><mi>t</mi><mo>,</mo><msub><mi>x</mi><mi>p</mi></msub><mo stretchy="false">)</mo></mrow><mo>⟩</mo></mrow></mrow></semantics></math></inline-formula>. First, we establish a weak form of intermittency under broad assumptions on <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="script">L</mi></semantics></math></inline-formula> and on a positive-definite noise correlator <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>B</mi><mo>=</mo><mi>B</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow></semantics></math></inline-formula>. We then examine strong intermittency, which emerges from the existence of a positive eigenvalue in a related lattice Schrödinger-type operator with potential <i>B</i>. Here, <i>B</i> does not have to be positive definite but must satisfy <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>∑</mo><mi>B</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>≥</mo><mn>0</mn></mrow></semantics></math></inline-formula>. The presence of such an eigenvalue intensifies the growth properties of the second moment <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>m</mi><mn>2</mn></msub></semantics></math></inline-formula>, revealing a more pronounced intermittent regime.
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spelling doaj-art-9e280f4af9814b50b4322db8cd19ccf92025-08-20T02:59:00ZengMDPI AGMathematics2227-73902025-02-0113568510.3390/math13050685Spectral Analysis of Lattice Schrödinger-Type Operators Associated with the Nonstationary Anderson Model and IntermittencyDan Han0Stanislav Molchanov1Boris Vainberg2Department of Mathematics, University of Louisville, Louisville, KY 40292, USADepartment of Mathematics and Statistics, University of North Carolina at Charlotte, Charlotte, NC 28223, USADepartment of Mathematics and Statistics, University of North Carolina at Charlotte, Charlotte, NC 28223, USAWe investigate the nonstationary parabolic Anderson problem <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mstyle scriptlevel="0" displaystyle="true"><mfrac><mrow><mo>∂</mo><mi>u</mi></mrow><mrow><mo>∂</mo><mi>t</mi></mrow></mfrac></mstyle><mo>=</mo><mi>ϰ</mi><mi mathvariant="script">L</mi><mi>u</mi><mrow><mo stretchy="false">(</mo><mi>t</mi><mo>,</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><mo>+</mo><msub><mi>ξ</mi><mi>t</mi></msub><mrow><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><mi>u</mi><mrow><mo stretchy="false">(</mo><mi>t</mi><mo>,</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><mo>,</mo><mspace width="1.em"></mspace><mi>u</mi><mrow><mo stretchy="false">(</mo><mn>0</mn><mo>,</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><mo>≡</mo><mn>1</mn><mo>,</mo><mspace width="1.em"></mspace><mrow><mo stretchy="false">(</mo><mi>t</mi><mo>,</mo><mi>x</mi><mo stretchy="false">)</mo></mrow><mo>∈</mo><mrow><mo>[</mo><mn>0</mn><mo>,</mo><mo>∞</mo><mo stretchy="false">)</mo></mrow><mo>×</mo><msup><mi>Z</mi><mi>d</mi></msup></mrow></semantics></math></inline-formula> where <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>ϰ</mi><mi mathvariant="script">L</mi></mrow></semantics></math></inline-formula> denotes a nonlocal Laplacian and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>ξ</mi><mi>t</mi></msub><mrow><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow></mrow></semantics></math></inline-formula> is a correlated white-noise potential. The irregularity of the solution is linked to the upper spectrum of certain multiparticle Schrödinger operators that govern the moment functions <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>m</mi><mi>p</mi></msub><mrow><mo stretchy="false">(</mo><mi>t</mi><mo>,</mo><msub><mi>x</mi><mn>1</mn></msub><mo>,</mo><msub><mi>x</mi><mn>2</mn></msub><mo>,</mo><mo>⋯</mo><mo>,</mo><msub><mi>x</mi><mi>p</mi></msub><mo stretchy="false">)</mo></mrow><mo>=</mo><mrow><mo>⟨</mo><mi>u</mi><mrow><mo stretchy="false">(</mo><mi>t</mi><mo>,</mo><msub><mi>x</mi><mn>1</mn></msub><mo stretchy="false">)</mo></mrow><mi>u</mi><mrow><mo stretchy="false">(</mo><mi>t</mi><mo>,</mo><msub><mi>x</mi><mn>2</mn></msub><mo stretchy="false">)</mo></mrow><mo>⋯</mo><mi>u</mi><mrow><mo stretchy="false">(</mo><mi>t</mi><mo>,</mo><msub><mi>x</mi><mi>p</mi></msub><mo stretchy="false">)</mo></mrow><mo>⟩</mo></mrow></mrow></semantics></math></inline-formula>. First, we establish a weak form of intermittency under broad assumptions on <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="script">L</mi></semantics></math></inline-formula> and on a positive-definite noise correlator <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>B</mi><mo>=</mo><mi>B</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo></mrow></semantics></math></inline-formula>. We then examine strong intermittency, which emerges from the existence of a positive eigenvalue in a related lattice Schrödinger-type operator with potential <i>B</i>. Here, <i>B</i> does not have to be positive definite but must satisfy <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>∑</mo><mi>B</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>≥</mo><mn>0</mn></mrow></semantics></math></inline-formula>. The presence of such an eigenvalue intensifies the growth properties of the second moment <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>m</mi><mn>2</mn></msub></semantics></math></inline-formula>, revealing a more pronounced intermittent regime.https://www.mdpi.com/2227-7390/13/5/685spectral analysisnonstationaryAnderson modelintermittency
spellingShingle Dan Han
Stanislav Molchanov
Boris Vainberg
Spectral Analysis of Lattice Schrödinger-Type Operators Associated with the Nonstationary Anderson Model and Intermittency
Mathematics
spectral analysis
nonstationary
Anderson model
intermittency
title Spectral Analysis of Lattice Schrödinger-Type Operators Associated with the Nonstationary Anderson Model and Intermittency
title_full Spectral Analysis of Lattice Schrödinger-Type Operators Associated with the Nonstationary Anderson Model and Intermittency
title_fullStr Spectral Analysis of Lattice Schrödinger-Type Operators Associated with the Nonstationary Anderson Model and Intermittency
title_full_unstemmed Spectral Analysis of Lattice Schrödinger-Type Operators Associated with the Nonstationary Anderson Model and Intermittency
title_short Spectral Analysis of Lattice Schrödinger-Type Operators Associated with the Nonstationary Anderson Model and Intermittency
title_sort spectral analysis of lattice schrodinger type operators associated with the nonstationary anderson model and intermittency
topic spectral analysis
nonstationary
Anderson model
intermittency
url https://www.mdpi.com/2227-7390/13/5/685
work_keys_str_mv AT danhan spectralanalysisoflatticeschrodingertypeoperatorsassociatedwiththenonstationaryandersonmodelandintermittency
AT stanislavmolchanov spectralanalysisoflatticeschrodingertypeoperatorsassociatedwiththenonstationaryandersonmodelandintermittency
AT borisvainberg spectralanalysisoflatticeschrodingertypeoperatorsassociatedwiththenonstationaryandersonmodelandintermittency