@article{45970,
  abstract     = {{<jats:p> We introduce a new phase field model for tumor growth where viscoelastic effects are taken into account. The model is derived from basic thermodynamical principles and consists of a convected Cahn–Hilliard equation with source terms for the tumor cells and a convected reaction–diffusion equation with boundary supply for the nutrient. Chemotactic terms, which are essential for the invasive behavior of tumors, are taken into account. The model is completed by a viscoelastic system consisting of the Navier–Stokes equation for the hydrodynamic quantities, and a general constitutive equation with stress relaxation for the left Cauchy–Green tensor associated with the elastic part of the total mechanical response of the viscoelastic material. For a specific choice of the elastic energy density and with an additional dissipative term accounting for stress diffusion, we prove existence of global-in-time weak solutions of the viscoelastic model for tumor growth in two space dimensions [Formula: see text] by the passage to the limit in a fully-discrete finite element scheme where a CFL condition, i.e. [Formula: see text], is required. </jats:p><jats:p> Moreover, in arbitrary dimensions [Formula: see text], we show stability and existence of solutions for the fully-discrete finite element scheme, where positive definiteness of the discrete Cauchy–Green tensor is proved with a regularization technique that was first introduced by Barrett and Boyaval [Existence and approximation of a (regularized) Oldroyd-B model, Math. Models Methods Appl. Sci. 21 (2011) 1783–1837]. After that, we improve the regularity results in arbitrary dimensions [Formula: see text] and in two dimensions [Formula: see text], where a CFL condition is required. Then, in two dimensions [Formula: see text], we pass to the limit in the discretization parameters and show that subsequences of discrete solutions converge to a global-in-time weak solution. Finally, we present numerical results in two dimensions [Formula: see text]. </jats:p>}},
  author       = {{Garcke, Harald and Kovács, Balázs and Trautwein, Dennis}},
  issn         = {{0218-2025}},
  journal      = {{Mathematical Models and Methods in Applied Sciences}},
  keywords     = {{Applied Mathematics, Modeling and Simulation}},
  number       = {{13}},
  pages        = {{2673--2758}},
  publisher    = {{World Scientific Pub Co Pte Ltd}},
  title        = {{{Viscoelastic Cahn–Hilliard models for tumor growth}}},
  doi          = {{10.1142/s0218202522500634}},
  volume       = {{32}},
  year         = {{2022}},
}