---
_id: '10007'
abstract:
- lang: eng
  text: The present thesis is concerned with the derivation of weak-strong uniqueness
    principles for curvature driven interface evolution problems not satisfying a
    comparison principle. The specific examples being treated are two-phase Navier-Stokes
    flow with surface tension, modeling the evolution of two incompressible, viscous
    and immiscible fluids separated by a sharp interface, and multiphase mean curvature
    flow, which serves as an idealized model for the motion of grain boundaries in
    an annealing polycrystalline material. Our main results - obtained in joint works
    with Julian Fischer, Tim Laux and Theresa M. Simon - state that prior to the formation
    of geometric singularities due to topology changes, the weak solution concept
    of Abels (Interfaces Free Bound. 9, 2007) to two-phase Navier-Stokes flow with
    surface tension and the weak solution concept of Laux and Otto (Calc. Var. Partial
    Differential Equations 55, 2016) to multiphase mean curvature flow (for networks
    in R^2 or double bubbles in R^3) represents the unique solution to these interface
    evolution problems within the class of classical solutions, respectively. To the
    best of the author's knowledge, for interface evolution problems not admitting
    a geometric comparison principle the derivation of a weak-strong uniqueness principle
    represented an open problem, so that the works contained in the present thesis
    constitute the first positive results in this direction. The key ingredient of
    our approach consists of the introduction of a novel concept of relative entropies
    for a class of curvature driven interface evolution problems, for which the associated
    energy contains an interfacial contribution being proportional to the surface
    area of the evolving (network of) interface(s). The interfacial part of the relative
    entropy gives sufficient control on the interface error between a weak and a classical
    solution, and its time evolution can be computed, at least in principle, for any
    energy dissipating weak solution concept. A resulting stability estimate for the
    relative entropy essentially entails the above mentioned weak-strong uniqueness
    principles. The present thesis contains a detailed introduction to our relative
    entropy approach, which in particular highlights potential applications to other
    problems in curvature driven interface evolution not treated in this thesis.
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Sebastian
  full_name: Hensel, Sebastian
  id: 4D23B7DA-F248-11E8-B48F-1D18A9856A87
  last_name: Hensel
  orcid: 0000-0001-7252-8072
citation:
  ama: 'Hensel S. Curvature driven interface evolution: Uniqueness properties of weak
    solution concepts. 2021. doi:<a href="https://doi.org/10.15479/at:ista:10007">10.15479/at:ista:10007</a>'
  apa: 'Hensel, S. (2021). <i>Curvature driven interface evolution: Uniqueness properties
    of weak solution concepts</i>. Institute of Science and Technology Austria. <a
    href="https://doi.org/10.15479/at:ista:10007">https://doi.org/10.15479/at:ista:10007</a>'
  chicago: 'Hensel, Sebastian. “Curvature Driven Interface Evolution: Uniqueness Properties
    of Weak Solution Concepts.” Institute of Science and Technology Austria, 2021.
    <a href="https://doi.org/10.15479/at:ista:10007">https://doi.org/10.15479/at:ista:10007</a>.'
  ieee: 'S. Hensel, “Curvature driven interface evolution: Uniqueness properties of
    weak solution concepts,” Institute of Science and Technology Austria, 2021.'
  ista: 'Hensel S. 2021. Curvature driven interface evolution: Uniqueness properties
    of weak solution concepts. Institute of Science and Technology Austria.'
  mla: 'Hensel, Sebastian. <i>Curvature Driven Interface Evolution: Uniqueness Properties
    of Weak Solution Concepts</i>. Institute of Science and Technology Austria, 2021,
    doi:<a href="https://doi.org/10.15479/at:ista:10007">10.15479/at:ista:10007</a>.'
  short: 'S. Hensel, Curvature Driven Interface Evolution: Uniqueness Properties of
    Weak Solution Concepts, Institute of Science and Technology Austria, 2021.'
corr_author: '1'
date_created: 2021-09-13T11:12:34Z
date_published: 2021-09-14T00:00:00Z
date_updated: 2025-07-10T11:54:41Z
day: '14'
ddc:
- '515'
degree_awarded: PhD
department:
- _id: GradSch
- _id: JuFi
doi: 10.15479/at:ista:10007
ec_funded: 1
file:
- access_level: closed
  checksum: c8475faaf0b680b4971f638f1db16347
  content_type: application/x-zip-compressed
  creator: shensel
  date_created: 2021-09-13T11:03:24Z
  date_updated: 2021-09-15T14:37:30Z
  file_id: '10008'
  file_name: thesis_final_Hensel.zip
  file_size: 15022154
  relation: source_file
- access_level: open_access
  checksum: 1a609937aa5275452822f45f2da17f07
  content_type: application/pdf
  creator: shensel
  date_created: 2021-09-13T14:18:56Z
  date_updated: 2021-09-14T09:52:47Z
  file_id: '10014'
  file_name: thesis_final_Hensel.pdf
  file_size: 6583638
  relation: main_file
file_date_updated: 2021-09-15T14:37:30Z
has_accepted_license: '1'
language:
- iso: eng
month: '09'
oa: 1
oa_version: Published Version
page: '300'
project:
- _id: 2564DBCA-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '665385'
  name: International IST Doctoral Program
- _id: 0aa76401-070f-11eb-9043-b5bb049fa26d
  call_identifier: H2020
  grant_number: '948819'
  name: Bridging Scales in Random Materials
publication_identifier:
  issn:
  - 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
  record:
  - id: '10012'
    relation: part_of_dissertation
    status: public
  - id: '10013'
    relation: part_of_dissertation
    status: public
  - id: '7489'
    relation: part_of_dissertation
    status: public
status: public
supervisor:
- first_name: Julian L
  full_name: Fischer, Julian L
  id: 2C12A0B0-F248-11E8-B48F-1D18A9856A87
  last_name: Fischer
  orcid: 0000-0002-0479-558X
title: 'Curvature driven interface evolution: Uniqueness properties of weak solution
  concepts'
type: dissertation
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2021'
...
