---
_id: '14715'
abstract:
- lang: eng
  text: We consider N trapped bosons in the mean-field limit with coupling constant
    λN = 1/(N − 1). The ground state of such systems exhibits Bose–Einstein condensation.
    We prove that the probability of finding ℓ particles outside the condensate wave
    function decays exponentially in ℓ.
acknowledgement: We thank Lea Boßmann, Phan Thành Nam and Simone Rademacher for helpful
  remarks. P.P. acknowledges funding by the Deutsche Forschungsgemeinschaft (DFG,
  German Research Foundation) - Grant No. SFB/TRR 352 “Mathematics of Many-Body Quantum
  Systems and Their Collective Phenomena.”
article_number: '121901'
article_processing_charge: Yes (in subscription journal)
article_type: original
arxiv: 1
author:
- first_name: David Johannes
  full_name: Mitrouskas, David Johannes
  id: cbddacee-2b11-11eb-a02e-a2e14d04e52d
  last_name: Mitrouskas
- first_name: Peter
  full_name: Pickl, Peter
  last_name: Pickl
citation:
  ama: Mitrouskas DJ, Pickl P. Exponential decay of the number of excitations in the
    weakly interacting Bose gas. <i>Journal of Mathematical Physics</i>. 2023;64(12).
    doi:<a href="https://doi.org/10.1063/5.0172199">10.1063/5.0172199</a>
  apa: Mitrouskas, D. J., &#38; Pickl, P. (2023). Exponential decay of the number
    of excitations in the weakly interacting Bose gas. <i>Journal of Mathematical
    Physics</i>. AIP Publishing. <a href="https://doi.org/10.1063/5.0172199">https://doi.org/10.1063/5.0172199</a>
  chicago: Mitrouskas, David Johannes, and Peter Pickl. “Exponential Decay of the
    Number of Excitations in the Weakly Interacting Bose Gas.” <i>Journal of Mathematical
    Physics</i>. AIP Publishing, 2023. <a href="https://doi.org/10.1063/5.0172199">https://doi.org/10.1063/5.0172199</a>.
  ieee: D. J. Mitrouskas and P. Pickl, “Exponential decay of the number of excitations
    in the weakly interacting Bose gas,” <i>Journal of Mathematical Physics</i>, vol.
    64, no. 12. AIP Publishing, 2023.
  ista: Mitrouskas DJ, Pickl P. 2023. Exponential decay of the number of excitations
    in the weakly interacting Bose gas. Journal of Mathematical Physics. 64(12), 121901.
  mla: Mitrouskas, David Johannes, and Peter Pickl. “Exponential Decay of the Number
    of Excitations in the Weakly Interacting Bose Gas.” <i>Journal of Mathematical
    Physics</i>, vol. 64, no. 12, 121901, AIP Publishing, 2023, doi:<a href="https://doi.org/10.1063/5.0172199">10.1063/5.0172199</a>.
  short: D.J. Mitrouskas, P. Pickl, Journal of Mathematical Physics 64 (2023).
date_created: 2023-12-31T23:01:02Z
date_published: 2023-12-01T00:00:00Z
date_updated: 2024-01-02T08:51:28Z
day: '01'
ddc:
- '510'
department:
- _id: RoSe
doi: 10.1063/5.0172199
external_id:
  arxiv:
  - '2307.11062'
file:
- access_level: open_access
  checksum: 66572f718a36465576cf0d6b3f7e01fc
  content_type: application/pdf
  creator: dernst
  date_created: 2024-01-02T08:45:07Z
  date_updated: 2024-01-02T08:45:07Z
  file_id: '14722'
  file_name: 2023_JourMathPhysics_Mitrouskas.pdf
  file_size: 4346922
  relation: main_file
  success: 1
file_date_updated: 2024-01-02T08:45:07Z
has_accepted_license: '1'
intvolume: '        64'
issue: '12'
language:
- iso: eng
month: '12'
oa: 1
oa_version: Published Version
publication: Journal of Mathematical Physics
publication_identifier:
  eissn:
  - 1089-7658
  issn:
  - 0022-2488
publication_status: published
publisher: AIP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: Exponential decay of the number of excitations in the weakly interacting Bose
  gas
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 64
year: '2023'
...
---
_id: '14854'
abstract:
- lang: eng
  text: "\r\nAbstract\r\nWe study the spectrum of the Fröhlich Hamiltonian for the
    polaron at fixed total momentum. We prove the existence of excited eigenvalues
    between the ground state energy and the essential spectrum at strong coupling.
    In fact, our main result shows that the number of excited energy bands diverges
    in the strong coupling limit. To prove this we derive upper bounds for the min-max
    values of the corresponding fiber Hamiltonians and compare them with the bottom
    of the essential spectrum, a lower bound on which was recently obtained by Brooks
    and Seiringer (Comm. Math. Phys. 404:1 (2023), 287–337). The upper bounds are
    given in terms of the ground state energy band shifted by momentum-independent
    excitation energies determined by an effective Hamiltonian of Bogoliubov type."
article_processing_charge: No
article_type: original
author:
- first_name: David Johannes
  full_name: Mitrouskas, David Johannes
  id: cbddacee-2b11-11eb-a02e-a2e14d04e52d
  last_name: Mitrouskas
- first_name: Robert
  full_name: Seiringer, Robert
  id: 4AFD0470-F248-11E8-B48F-1D18A9856A87
  last_name: Seiringer
  orcid: 0000-0002-6781-0521
citation:
  ama: Mitrouskas DJ, Seiringer R. Ubiquity of bound states for the strongly coupled
    polaron. <i>Pure and Applied Analysis</i>. 2023;5(4):973-1008. doi:<a href="https://doi.org/10.2140/paa.2023.5.973">10.2140/paa.2023.5.973</a>
  apa: Mitrouskas, D. J., &#38; Seiringer, R. (2023). Ubiquity of bound states for
    the strongly coupled polaron. <i>Pure and Applied Analysis</i>. Mathematical Sciences
    Publishers. <a href="https://doi.org/10.2140/paa.2023.5.973">https://doi.org/10.2140/paa.2023.5.973</a>
  chicago: Mitrouskas, David Johannes, and Robert Seiringer. “Ubiquity of Bound States
    for the Strongly Coupled Polaron.” <i>Pure and Applied Analysis</i>. Mathematical
    Sciences Publishers, 2023. <a href="https://doi.org/10.2140/paa.2023.5.973">https://doi.org/10.2140/paa.2023.5.973</a>.
  ieee: D. J. Mitrouskas and R. Seiringer, “Ubiquity of bound states for the strongly
    coupled polaron,” <i>Pure and Applied Analysis</i>, vol. 5, no. 4. Mathematical
    Sciences Publishers, pp. 973–1008, 2023.
  ista: Mitrouskas DJ, Seiringer R. 2023. Ubiquity of bound states for the strongly
    coupled polaron. Pure and Applied Analysis. 5(4), 973–1008.
  mla: Mitrouskas, David Johannes, and Robert Seiringer. “Ubiquity of Bound States
    for the Strongly Coupled Polaron.” <i>Pure and Applied Analysis</i>, vol. 5, no.
    4, Mathematical Sciences Publishers, 2023, pp. 973–1008, doi:<a href="https://doi.org/10.2140/paa.2023.5.973">10.2140/paa.2023.5.973</a>.
  short: D.J. Mitrouskas, R. Seiringer, Pure and Applied Analysis 5 (2023) 973–1008.
date_created: 2024-01-22T08:24:23Z
date_published: 2023-12-15T00:00:00Z
date_updated: 2024-01-23T12:55:12Z
day: '15'
department:
- _id: RoSe
doi: 10.2140/paa.2023.5.973
intvolume: '         5'
issue: '4'
keyword:
- General Medicine
language:
- iso: eng
month: '12'
oa_version: None
page: 973-1008
publication: Pure and Applied Analysis
publication_identifier:
  issn:
  - 2578-5885
  - 2578-5893
publication_status: published
publisher: Mathematical Sciences Publishers
quality_controlled: '1'
status: public
title: Ubiquity of bound states for the strongly coupled polaron
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 5
year: '2023'
...
---
_id: '13178'
abstract:
- lang: eng
  text: We consider the large polaron described by the Fröhlich Hamiltonian and study
    its energy-momentum relation defined as the lowest possible energy as a function
    of the total momentum. Using a suitable family of trial states, we derive an optimal
    parabolic upper bound for the energy-momentum relation in the limit of strong
    coupling. The upper bound consists of a momentum independent term that agrees
    with the predicted two-term expansion for the ground state energy of the strongly
    coupled polaron at rest and a term that is quadratic in the momentum with coefficient
    given by the inverse of twice the classical effective mass introduced by Landau
    and Pekar.
acknowledgement: This research was supported by the European Research Council (ERC)
  under the European Union’s Horizon 2020 research and innovation programme grant
  agreement No. 694227 (R.S.) and the Maria Skłodowska-Curie grant agreement No. 665386
  (K.M.).
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: David Johannes
  full_name: Mitrouskas, David Johannes
  id: cbddacee-2b11-11eb-a02e-a2e14d04e52d
  last_name: Mitrouskas
- first_name: Krzysztof
  full_name: Mysliwy, Krzysztof
  id: 316457FC-F248-11E8-B48F-1D18A9856A87
  last_name: Mysliwy
- first_name: Robert
  full_name: Seiringer, Robert
  id: 4AFD0470-F248-11E8-B48F-1D18A9856A87
  last_name: Seiringer
  orcid: 0000-0002-6781-0521
citation:
  ama: Mitrouskas DJ, Mysliwy K, Seiringer R. Optimal parabolic upper bound for the
    energy-momentum relation of a strongly coupled polaron. <i>Forum of Mathematics</i>.
    2023;11:1-52. doi:<a href="https://doi.org/10.1017/fms.2023.45">10.1017/fms.2023.45</a>
  apa: Mitrouskas, D. J., Mysliwy, K., &#38; Seiringer, R. (2023). Optimal parabolic
    upper bound for the energy-momentum relation of a strongly coupled polaron. <i>Forum
    of Mathematics</i>. Cambridge University Press. <a href="https://doi.org/10.1017/fms.2023.45">https://doi.org/10.1017/fms.2023.45</a>
  chicago: Mitrouskas, David Johannes, Krzysztof Mysliwy, and Robert Seiringer. “Optimal
    Parabolic Upper Bound for the Energy-Momentum Relation of a Strongly Coupled Polaron.”
    <i>Forum of Mathematics</i>. Cambridge University Press, 2023. <a href="https://doi.org/10.1017/fms.2023.45">https://doi.org/10.1017/fms.2023.45</a>.
  ieee: D. J. Mitrouskas, K. Mysliwy, and R. Seiringer, “Optimal parabolic upper bound
    for the energy-momentum relation of a strongly coupled polaron,” <i>Forum of Mathematics</i>,
    vol. 11. Cambridge University Press, pp. 1–52, 2023.
  ista: Mitrouskas DJ, Mysliwy K, Seiringer R. 2023. Optimal parabolic upper bound
    for the energy-momentum relation of a strongly coupled polaron. Forum of Mathematics.
    11, 1–52.
  mla: Mitrouskas, David Johannes, et al. “Optimal Parabolic Upper Bound for the Energy-Momentum
    Relation of a Strongly Coupled Polaron.” <i>Forum of Mathematics</i>, vol. 11,
    Cambridge University Press, 2023, pp. 1–52, doi:<a href="https://doi.org/10.1017/fms.2023.45">10.1017/fms.2023.45</a>.
  short: D.J. Mitrouskas, K. Mysliwy, R. Seiringer, Forum of Mathematics 11 (2023)
    1–52.
date_created: 2023-07-02T22:00:43Z
date_published: 2023-06-13T00:00:00Z
date_updated: 2023-11-02T12:30:50Z
day: '13'
ddc:
- '500'
department:
- _id: RoSe
doi: 10.1017/fms.2023.45
ec_funded: 1
external_id:
  arxiv:
  - '2203.02454'
  isi:
  - '001005008800001'
file:
- access_level: open_access
  checksum: f672eb7dd015c472c9a04f1b9bf9df7d
  content_type: application/pdf
  creator: alisjak
  date_created: 2023-07-03T10:36:25Z
  date_updated: 2023-07-03T10:36:25Z
  file_id: '13186'
  file_name: 2023_ForumofMathematics.Sigma_Mitrouskas.pdf
  file_size: 943192
  relation: main_file
  success: 1
file_date_updated: 2023-07-03T10:36:25Z
has_accepted_license: '1'
intvolume: '        11'
isi: 1
language:
- iso: eng
month: '06'
oa: 1
oa_version: Published Version
page: 1-52
project:
- _id: 25C6DC12-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '694227'
  name: Analysis of quantum many-body systems
publication: Forum of Mathematics
publication_identifier:
  eissn:
  - 2050-5094
publication_status: published
publisher: Cambridge University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: Optimal parabolic upper bound for the energy-momentum relation of a strongly
  coupled polaron
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: journal_article
user_id: 3E5EF7F0-F248-11E8-B48F-1D18A9856A87
volume: 11
year: '2023'
...
---
_id: '14192'
abstract:
- lang: eng
  text: For the Fröhlich model of the large polaron, we prove that the ground state
    energy as a function of the total momentum has a unique global minimum at momentum
    zero. This implies the non-existence of a ground state of the translation invariant
    Fröhlich Hamiltonian and thus excludes the possibility of a localization transition
    at finite coupling.
acknowledgement: D.M. and K.M. thank Robert Seiringer for helpful discussions. Open
  access funding provided by Institute of Science and Technology (IST Austria). Financial
  support from the Agence Nationale de la Recherche (ANR) through the projects ANR-17-CE40-0016,
  ANR-17-CE40-0007-01, ANR-17-EURE-0002 (J.L.) and from the European Union’s Horizon
  2020 research and innovation programme under the Maria Skłodowska-Curie grant agreement
  No. 665386 (K.M.) is gratefully acknowledged.
article_number: '17'
article_processing_charge: Yes (via OA deal)
article_type: original
arxiv: 1
author:
- first_name: Jonas
  full_name: Lampart, Jonas
  last_name: Lampart
- first_name: David Johannes
  full_name: Mitrouskas, David Johannes
  id: cbddacee-2b11-11eb-a02e-a2e14d04e52d
  last_name: Mitrouskas
- first_name: Krzysztof
  full_name: Mysliwy, Krzysztof
  id: 316457FC-F248-11E8-B48F-1D18A9856A87
  last_name: Mysliwy
citation:
  ama: Lampart J, Mitrouskas DJ, Mysliwy K. On the global minimum of the energy–momentum
    relation for the polaron. <i>Mathematical Physics, Analysis and Geometry</i>.
    2023;26(3). doi:<a href="https://doi.org/10.1007/s11040-023-09460-x">10.1007/s11040-023-09460-x</a>
  apa: Lampart, J., Mitrouskas, D. J., &#38; Mysliwy, K. (2023). On the global minimum
    of the energy–momentum relation for the polaron. <i>Mathematical Physics, Analysis
    and Geometry</i>. Springer Nature. <a href="https://doi.org/10.1007/s11040-023-09460-x">https://doi.org/10.1007/s11040-023-09460-x</a>
  chicago: Lampart, Jonas, David Johannes Mitrouskas, and Krzysztof Mysliwy. “On the
    Global Minimum of the Energy–Momentum Relation for the Polaron.” <i>Mathematical
    Physics, Analysis and Geometry</i>. Springer Nature, 2023. <a href="https://doi.org/10.1007/s11040-023-09460-x">https://doi.org/10.1007/s11040-023-09460-x</a>.
  ieee: J. Lampart, D. J. Mitrouskas, and K. Mysliwy, “On the global minimum of the
    energy–momentum relation for the polaron,” <i>Mathematical Physics, Analysis and
    Geometry</i>, vol. 26, no. 3. Springer Nature, 2023.
  ista: Lampart J, Mitrouskas DJ, Mysliwy K. 2023. On the global minimum of the energy–momentum
    relation for the polaron. Mathematical Physics, Analysis and Geometry. 26(3),
    17.
  mla: Lampart, Jonas, et al. “On the Global Minimum of the Energy–Momentum Relation
    for the Polaron.” <i>Mathematical Physics, Analysis and Geometry</i>, vol. 26,
    no. 3, 17, Springer Nature, 2023, doi:<a href="https://doi.org/10.1007/s11040-023-09460-x">10.1007/s11040-023-09460-x</a>.
  short: J. Lampart, D.J. Mitrouskas, K. Mysliwy, Mathematical Physics, Analysis and
    Geometry 26 (2023).
date_created: 2023-08-22T14:09:47Z
date_published: 2023-07-26T00:00:00Z
date_updated: 2023-12-13T12:16:19Z
day: '26'
ddc:
- '510'
department:
- _id: RoSe
doi: 10.1007/s11040-023-09460-x
external_id:
  arxiv:
  - '2206.14708'
  isi:
  - '001032992600001'
file:
- access_level: open_access
  checksum: f0941cc66cb3ed06a12ca4b7e356cfd6
  content_type: application/pdf
  creator: dernst
  date_created: 2023-08-23T10:59:15Z
  date_updated: 2023-08-23T10:59:15Z
  file_id: '14225'
  file_name: 2023_MathPhysics_Lampart.pdf
  file_size: 317026
  relation: main_file
  success: 1
file_date_updated: 2023-08-23T10:59:15Z
has_accepted_license: '1'
intvolume: '        26'
isi: 1
issue: '3'
keyword:
- Geometry and Topology
- Mathematical Physics
language:
- iso: eng
month: '07'
oa: 1
oa_version: Published Version
publication: Mathematical Physics, Analysis and Geometry
publication_identifier:
  eissn:
  - 1572-9656
  issn:
  - 1385-0172
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: On the global minimum of the energy–momentum relation for the polaron
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 26
year: '2023'
...
---
_id: '12430'
abstract:
- lang: eng
  text: We study the time evolution of the Nelson model in a mean-field limit in which
    N nonrelativistic bosons weakly couple (with respect to the particle number) to
    a positive or zero mass quantized scalar field. Our main result is the derivation
    of the Bogoliubov dynamics and higher-order corrections. More precisely, we prove
    the convergence of the approximate wave function to the many-body wave function
    in norm, with a convergence rate proportional to the number of corrections taken
    into account in the approximation. We prove an analogous result for the unitary
    propagator. As an application, we derive a simple system of partial differential
    equations describing the time evolution of the first- and second-order approximations
    to the one-particle reduced density matrices of the particles and the quantum
    field, respectively.
article_number: '2350006'
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Marco
  full_name: Falconi, Marco
  last_name: Falconi
- first_name: Nikolai K
  full_name: Leopold, Nikolai K
  id: 4BC40BEC-F248-11E8-B48F-1D18A9856A87
  last_name: Leopold
  orcid: 0000-0002-0495-6822
- first_name: David Johannes
  full_name: Mitrouskas, David Johannes
  id: cbddacee-2b11-11eb-a02e-a2e14d04e52d
  last_name: Mitrouskas
- first_name: Sören P
  full_name: Petrat, Sören P
  id: 40AC02DC-F248-11E8-B48F-1D18A9856A87
  last_name: Petrat
  orcid: 0000-0002-9166-5889
citation:
  ama: Falconi M, Leopold NK, Mitrouskas DJ, Petrat SP. Bogoliubov dynamics and higher-order
    corrections for the regularized Nelson model. <i>Reviews in Mathematical Physics</i>.
    2023;35(4). doi:<a href="https://doi.org/10.1142/S0129055X2350006X">10.1142/S0129055X2350006X</a>
  apa: Falconi, M., Leopold, N. K., Mitrouskas, D. J., &#38; Petrat, S. P. (2023).
    Bogoliubov dynamics and higher-order corrections for the regularized Nelson model.
    <i>Reviews in Mathematical Physics</i>. World Scientific Publishing. <a href="https://doi.org/10.1142/S0129055X2350006X">https://doi.org/10.1142/S0129055X2350006X</a>
  chicago: Falconi, Marco, Nikolai K Leopold, David Johannes Mitrouskas, and Sören
    P Petrat. “Bogoliubov Dynamics and Higher-Order Corrections for the Regularized
    Nelson Model.” <i>Reviews in Mathematical Physics</i>. World Scientific Publishing,
    2023. <a href="https://doi.org/10.1142/S0129055X2350006X">https://doi.org/10.1142/S0129055X2350006X</a>.
  ieee: M. Falconi, N. K. Leopold, D. J. Mitrouskas, and S. P. Petrat, “Bogoliubov
    dynamics and higher-order corrections for the regularized Nelson model,” <i>Reviews
    in Mathematical Physics</i>, vol. 35, no. 4. World Scientific Publishing, 2023.
  ista: Falconi M, Leopold NK, Mitrouskas DJ, Petrat SP. 2023. Bogoliubov dynamics
    and higher-order corrections for the regularized Nelson model. Reviews in Mathematical
    Physics. 35(4), 2350006.
  mla: Falconi, Marco, et al. “Bogoliubov Dynamics and Higher-Order Corrections for
    the Regularized Nelson Model.” <i>Reviews in Mathematical Physics</i>, vol. 35,
    no. 4, 2350006, World Scientific Publishing, 2023, doi:<a href="https://doi.org/10.1142/S0129055X2350006X">10.1142/S0129055X2350006X</a>.
  short: M. Falconi, N.K. Leopold, D.J. Mitrouskas, S.P. Petrat, Reviews in Mathematical
    Physics 35 (2023).
date_created: 2023-01-29T23:00:59Z
date_published: 2023-01-09T00:00:00Z
date_updated: 2023-08-16T11:47:27Z
day: '09'
department:
- _id: RoSe
doi: 10.1142/S0129055X2350006X
external_id:
  arxiv:
  - '2110.00458'
  isi:
  - '000909760300001'
intvolume: '        35'
isi: 1
issue: '4'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: ' https://doi.org/10.48550/arXiv.2110.00458'
month: '01'
oa: 1
oa_version: Preprint
publication: Reviews in Mathematical Physics
publication_identifier:
  issn:
  - 0129-055X
publication_status: published
publisher: World Scientific Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: Bogoliubov dynamics and higher-order corrections for the regularized Nelson
  model
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 35
year: '2023'
...
---
_id: '14889'
abstract:
- lang: eng
  text: We consider the Fröhlich Hamiltonian with large coupling constant α. For initial
    data of Pekar product form with coherent phonon field and with the electron minimizing
    the corresponding energy, we provide a norm approximation of the evolution, valid
    up to times of order α2. The approximation is given in terms of a Pekar product
    state, evolved through the Landau-Pekar equations, corrected by a Bogoliubov dynamics
    taking quantum fluctuations into account. This allows us to show that the Landau-Pekar
    equations approximately describe the evolution of the electron- and one-phonon
    reduced density matrices under the Fröhlich dynamics up to times of order α2.
acknowledgement: "Financial support by the European Union’s Horizon 2020 research
  and innovation programme\r\nunder the Marie Skłodowska-Curie grant agreement No.
  754411 (S.R.) and the European\r\nResearch Council under grant agreement No. 694227
  (N.L. and R.S.), as well as by the SNSF\r\nEccellenza project PCEFP2 181153 (N.L.),
  the NCCR SwissMAP (N.L. and B.S.) and by the\r\nDeutsche Forschungsgemeinschaft
  (DFG) through the Research Training Group 1838: Spectral\r\nTheory and Dynamics
  of Quantum Systems (D.M.) is gratefully acknowledged. B.S. gratefully\r\nacknowledges
  financial support from the Swiss National Science Foundation through the Grant\r\n“Dynamical
  and energetic properties of Bose-Einstein condensates” and from the European\r\nResearch
  Council through the ERC-AdG CLaQS (grant agreement No 834782). D.M. thanks\r\nMarcel
  Griesemer for helpful discussions."
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Nikolai K
  full_name: Leopold, Nikolai K
  id: 4BC40BEC-F248-11E8-B48F-1D18A9856A87
  last_name: Leopold
  orcid: 0000-0002-0495-6822
- first_name: David Johannes
  full_name: Mitrouskas, David Johannes
  id: cbddacee-2b11-11eb-a02e-a2e14d04e52d
  last_name: Mitrouskas
- first_name: Simone Anna Elvira
  full_name: Rademacher, Simone Anna Elvira
  id: 856966FE-A408-11E9-977E-802DE6697425
  last_name: Rademacher
  orcid: 0000-0001-5059-4466
- first_name: Benjamin
  full_name: Schlein, Benjamin
  last_name: Schlein
- first_name: Robert
  full_name: Seiringer, Robert
  id: 4AFD0470-F248-11E8-B48F-1D18A9856A87
  last_name: Seiringer
  orcid: 0000-0002-6781-0521
citation:
  ama: Leopold NK, Mitrouskas DJ, Rademacher SAE, Schlein B, Seiringer R. Landau–Pekar
    equations and quantum fluctuations for the dynamics of a strongly coupled polaron.
    <i>Pure and Applied Analysis</i>. 2021;3(4):653-676. doi:<a href="https://doi.org/10.2140/paa.2021.3.653">10.2140/paa.2021.3.653</a>
  apa: Leopold, N. K., Mitrouskas, D. J., Rademacher, S. A. E., Schlein, B., &#38;
    Seiringer, R. (2021). Landau–Pekar equations and quantum fluctuations for the
    dynamics of a strongly coupled polaron. <i>Pure and Applied Analysis</i>. Mathematical
    Sciences Publishers. <a href="https://doi.org/10.2140/paa.2021.3.653">https://doi.org/10.2140/paa.2021.3.653</a>
  chicago: Leopold, Nikolai K, David Johannes Mitrouskas, Simone Anna Elvira Rademacher,
    Benjamin Schlein, and Robert Seiringer. “Landau–Pekar Equations and Quantum Fluctuations
    for the Dynamics of a Strongly Coupled Polaron.” <i>Pure and Applied Analysis</i>.
    Mathematical Sciences Publishers, 2021. <a href="https://doi.org/10.2140/paa.2021.3.653">https://doi.org/10.2140/paa.2021.3.653</a>.
  ieee: N. K. Leopold, D. J. Mitrouskas, S. A. E. Rademacher, B. Schlein, and R. Seiringer,
    “Landau–Pekar equations and quantum fluctuations for the dynamics of a strongly
    coupled polaron,” <i>Pure and Applied Analysis</i>, vol. 3, no. 4. Mathematical
    Sciences Publishers, pp. 653–676, 2021.
  ista: Leopold NK, Mitrouskas DJ, Rademacher SAE, Schlein B, Seiringer R. 2021. Landau–Pekar
    equations and quantum fluctuations for the dynamics of a strongly coupled polaron.
    Pure and Applied Analysis. 3(4), 653–676.
  mla: Leopold, Nikolai K., et al. “Landau–Pekar Equations and Quantum Fluctuations
    for the Dynamics of a Strongly Coupled Polaron.” <i>Pure and Applied Analysis</i>,
    vol. 3, no. 4, Mathematical Sciences Publishers, 2021, pp. 653–76, doi:<a href="https://doi.org/10.2140/paa.2021.3.653">10.2140/paa.2021.3.653</a>.
  short: N.K. Leopold, D.J. Mitrouskas, S.A.E. Rademacher, B. Schlein, R. Seiringer,
    Pure and Applied Analysis 3 (2021) 653–676.
date_created: 2024-01-28T23:01:43Z
date_published: 2021-10-01T00:00:00Z
date_updated: 2024-02-05T10:02:45Z
day: '01'
department:
- _id: RoSe
doi: 10.2140/paa.2021.3.653
ec_funded: 1
external_id:
  arxiv:
  - '2005.02098'
intvolume: '         3'
issue: '4'
language:
- iso: eng
main_file_link:
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  url: https://doi.org/10.48550/arXiv.2005.02098
month: '10'
oa: 1
oa_version: Preprint
page: 653-676
project:
- _id: 260C2330-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '754411'
  name: ISTplus - Postdoctoral Fellowships
- _id: 25C6DC12-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '694227'
  name: Analysis of quantum many-body systems
publication: Pure and Applied Analysis
publication_identifier:
  eissn:
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  issn:
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publication_status: published
publisher: Mathematical Sciences Publishers
quality_controlled: '1'
scopus_import: '1'
status: public
title: Landau–Pekar equations and quantum fluctuations for the dynamics of a strongly
  coupled polaron
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 3
year: '2021'
...
---
_id: '9246'
abstract:
- lang: eng
  text: We consider the Fröhlich Hamiltonian in a mean-field limit where many bosonic
    particles weakly couple to the quantized phonon field. For large particle numbers
    and a suitably small coupling, we show that the dynamics of the system is approximately
    described by the Landau–Pekar equations. These describe a Bose–Einstein condensate
    interacting with a classical polarization field, whose dynamics is effected by
    the condensate, i.e., the back-reaction of the phonons that are created by the
    particles during the time evolution is of leading order.
acknowledgement: "Financial support by the European Research Council (ERC) under the\r\nEuropean
  Union’s Horizon 2020 research and innovation programme (Grant Agreement\r\nNo 694227;
  N.L and R.S.), the SNSF Eccellenza Project PCEFP2 181153 (N.L) and the\r\nDeutsche
  Forschungsgemeinschaft (DFG) through the Research TrainingGroup 1838: Spectral\r\nTheory
  and Dynamics of Quantum Systems (D.M.) is gratefully acknowledged. N.L.\r\ngratefully
  acknowledges support from the NCCRSwissMAP and would like to thank Simone\r\nRademacher
  and Benjamin Schlein for interesting discussions about the time-evolution of\r\nthe
  polaron at strong coupling. D.M. thanks Marcel Griesemer and Andreas Wünsch for\r\nextensive
  discussions about the Fröhlich polaron."
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Nikolai K
  full_name: Leopold, Nikolai K
  id: 4BC40BEC-F248-11E8-B48F-1D18A9856A87
  last_name: Leopold
  orcid: 0000-0002-0495-6822
- first_name: David Johannes
  full_name: Mitrouskas, David Johannes
  id: cbddacee-2b11-11eb-a02e-a2e14d04e52d
  last_name: Mitrouskas
- first_name: Robert
  full_name: Seiringer, Robert
  id: 4AFD0470-F248-11E8-B48F-1D18A9856A87
  last_name: Seiringer
  orcid: 0000-0002-6781-0521
citation:
  ama: Leopold NK, Mitrouskas DJ, Seiringer R. Derivation of the Landau–Pekar equations
    in a many-body mean-field limit. <i>Archive for Rational Mechanics and Analysis</i>.
    2021;240:383-417. doi:<a href="https://doi.org/10.1007/s00205-021-01616-9">10.1007/s00205-021-01616-9</a>
  apa: Leopold, N. K., Mitrouskas, D. J., &#38; Seiringer, R. (2021). Derivation of
    the Landau–Pekar equations in a many-body mean-field limit. <i>Archive for Rational
    Mechanics and Analysis</i>. Springer Nature. <a href="https://doi.org/10.1007/s00205-021-01616-9">https://doi.org/10.1007/s00205-021-01616-9</a>
  chicago: Leopold, Nikolai K, David Johannes Mitrouskas, and Robert Seiringer. “Derivation
    of the Landau–Pekar Equations in a Many-Body Mean-Field Limit.” <i>Archive for
    Rational Mechanics and Analysis</i>. Springer Nature, 2021. <a href="https://doi.org/10.1007/s00205-021-01616-9">https://doi.org/10.1007/s00205-021-01616-9</a>.
  ieee: N. K. Leopold, D. J. Mitrouskas, and R. Seiringer, “Derivation of the Landau–Pekar
    equations in a many-body mean-field limit,” <i>Archive for Rational Mechanics
    and Analysis</i>, vol. 240. Springer Nature, pp. 383–417, 2021.
  ista: Leopold NK, Mitrouskas DJ, Seiringer R. 2021. Derivation of the Landau–Pekar
    equations in a many-body mean-field limit. Archive for Rational Mechanics and
    Analysis. 240, 383–417.
  mla: Leopold, Nikolai K., et al. “Derivation of the Landau–Pekar Equations in a
    Many-Body Mean-Field Limit.” <i>Archive for Rational Mechanics and Analysis</i>,
    vol. 240, Springer Nature, 2021, pp. 383–417, doi:<a href="https://doi.org/10.1007/s00205-021-01616-9">10.1007/s00205-021-01616-9</a>.
  short: N.K. Leopold, D.J. Mitrouskas, R. Seiringer, Archive for Rational Mechanics
    and Analysis 240 (2021) 383–417.
date_created: 2021-03-14T23:01:34Z
date_published: 2021-02-26T00:00:00Z
date_updated: 2023-08-07T14:12:27Z
day: '26'
ddc:
- '510'
department:
- _id: RoSe
doi: 10.1007/s00205-021-01616-9
ec_funded: 1
external_id:
  arxiv:
  - '2001.03993'
  isi:
  - '000622226200001'
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- access_level: open_access
  checksum: 23449e44dc5132501a5c86e70638800f
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  creator: dernst
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  date_updated: 2021-03-22T08:31:29Z
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  file_name: 2021_ArchRationalMechAnal_Leopold.pdf
  file_size: 558006
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  success: 1
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intvolume: '       240'
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language:
- iso: eng
month: '02'
oa: 1
oa_version: Published Version
page: 383-417
project:
- _id: 25C6DC12-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '694227'
  name: Analysis of quantum many-body systems
publication: Archive for Rational Mechanics and Analysis
publication_identifier:
  eissn:
  - '14320673'
  issn:
  - '00039527'
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Derivation of the Landau–Pekar equations in a many-body mean-field limit
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  image: /images/cc_by.png
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  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: journal_article
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 240
year: '2021'
...
---
_id: '9333'
abstract:
- lang: eng
  text: We revise a previous result about the Fröhlich dynamics in the strong coupling
    limit obtained in Griesemer (Rev Math Phys 29(10):1750030, 2017). In the latter
    it was shown that the Fröhlich time evolution applied to the initial state φ0⊗ξα,
    where φ0 is the electron ground state of the Pekar energy functional and ξα the
    associated coherent state of the phonons, can be approximated by a global phase
    for times small compared to α2. In the present note we prove that a similar approximation
    holds for t=O(α2) if one includes a nontrivial effective dynamics for the phonons
    that is generated by an operator proportional to α−2 and quadratic in creation
    and annihilation operators. Our result implies that the electron ground state
    remains close to its initial state for times of order α2, while the phonon fluctuations
    around the coherent state ξα can be described by a time-dependent Bogoliubov transformation.
acknowledgement: 'I thank Marcel Griesemer for many interesting discussions about
  the Fröhlich polaron and also for valuable comments on this manuscript. Helpful
  discussions with Nikolai Leopold and Robert Seiringer are also gratefully acknowledged.
  This work was partially supported by the Deutsche Forschungsgemeinschaft (DFG) through
  the Research Training Group 1838: Spectral Theory and Dynamics of Quantum Systems.
  Open Access funding enabled and organized by Projekt DEAL.'
article_number: '45'
article_processing_charge: No
article_type: original
author:
- first_name: David Johannes
  full_name: Mitrouskas, David Johannes
  id: cbddacee-2b11-11eb-a02e-a2e14d04e52d
  last_name: Mitrouskas
citation:
  ama: Mitrouskas DJ. A note on the Fröhlich dynamics in the strong coupling limit.
    <i>Letters in Mathematical Physics</i>. 2021;111. doi:<a href="https://doi.org/10.1007/s11005-021-01380-7">10.1007/s11005-021-01380-7</a>
  apa: Mitrouskas, D. J. (2021). A note on the Fröhlich dynamics in the strong coupling
    limit. <i>Letters in Mathematical Physics</i>. Springer Nature. <a href="https://doi.org/10.1007/s11005-021-01380-7">https://doi.org/10.1007/s11005-021-01380-7</a>
  chicago: Mitrouskas, David Johannes. “A Note on the Fröhlich Dynamics in the Strong
    Coupling Limit.” <i>Letters in Mathematical Physics</i>. Springer Nature, 2021.
    <a href="https://doi.org/10.1007/s11005-021-01380-7">https://doi.org/10.1007/s11005-021-01380-7</a>.
  ieee: D. J. Mitrouskas, “A note on the Fröhlich dynamics in the strong coupling
    limit,” <i>Letters in Mathematical Physics</i>, vol. 111. Springer Nature, 2021.
  ista: Mitrouskas DJ. 2021. A note on the Fröhlich dynamics in the strong coupling
    limit. Letters in Mathematical Physics. 111, 45.
  mla: Mitrouskas, David Johannes. “A Note on the Fröhlich Dynamics in the Strong
    Coupling Limit.” <i>Letters in Mathematical Physics</i>, vol. 111, 45, Springer
    Nature, 2021, doi:<a href="https://doi.org/10.1007/s11005-021-01380-7">10.1007/s11005-021-01380-7</a>.
  short: D.J. Mitrouskas, Letters in Mathematical Physics 111 (2021).
date_created: 2021-04-18T22:01:41Z
date_published: 2021-04-05T00:00:00Z
date_updated: 2023-08-08T13:09:28Z
day: '05'
ddc:
- '510'
department:
- _id: RoSe
doi: 10.1007/s11005-021-01380-7
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  - '000637359300002'
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oa_version: Published Version
publication: Letters in Mathematical Physics
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  eissn:
  - '15730530'
  issn:
  - '03779017'
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: A note on the Fröhlich dynamics in the strong coupling limit
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: journal_article
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 111
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...
