Research Article
Existence, Nonexistence, and Stability of Solutions for a Delayed
Plate Equation with the Logarithmic Source
Hazal Yüksekkaya,
1
Erhan Pișkin,
1
Salah Mahmoud Boulaaras ,
2,3
Bahri Belkacem Cherif ,
2,4
and Sulima Ahmed Zubair
2,5
1
Department of Mathematics, Dicle University, Diyarbakir, Turkey
2
Department of Mathematics, College of Sciences and Arts, ArRas, Qassim University, Saudi Arabia
3
Laboratory of Fundamental and Applied Mathematics of Oran (LMFAO), University of Oran 1, Oran, 31000 Oran, Algeria
4
Preparatory Institute for Engineering Studies in Sfax, Tunisia
5
Department of Mathematics, College of Education, Juba University, Sudan
Correspondence should be addressed to Sulima Ahmed Zubair; sulimaa2021@gmail.com
Received 12 May 2021; Accepted 16 June 2021; Published 28 June 2021
Academic Editor: Kamyar Hosseini
Copyright © 2021 Hazal Yüksekkaya et al. This is an open access article distributed under the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is
properly cited.
In this work, we study a plate equation with time delay in the velocity, frictional damping, and logarithmic source term. Firstly, we
obtain the local and global existence of solutions by the logarithmic Sobolev inequality and the Faedo-Galerkin method. Moreover,
we prove the stability and nonexistence results by the perturbed energy and potential well methods.
1. Introduction
In this article, we consider a plate equation with frictional
damping, delay, and logarithmic terms as follows:
u
tt
+ Δ
2
u + αu
t
t ðÞ + βu
t
x, t − τ ð Þ = u ln u jj
γ
for x, t ð Þ ∈ Ω × 0,∞ ð Þ,
ux, t ð Þ =
∂ux, t ð Þ
∂υ
=0 for x, t ð Þ ∈ ∂Ω × 0,∞ ð Þ,
ux,0 ð Þ = u
0
x ðÞ, u
t
x,0 ð Þ = u
1
x ðÞ for x ∈ Ω,
u
t
x, t ð Þ = j
0
x, t ð Þ for x, t ð Þ ∈ Ω × −τ,0 ð Þ,
8
>
>
>
>
>
>
<
>
>
>
>
>
>
:
ð1Þ
where Ω ⊂ R
N
, N ≥ 1, is a bounded domain with smooth
boundary ∂Ω. τ >0 denotes time delay, and α, β, and γ are
real numbers that will be specified later. Generally, logarith-
mic nonlinearity seems to be in supersymmetric field theories
and in cosmological inflation. From quantum field theory,
that kind of (ujuj
p−2
ln juj
k
) logarithmic source term seems
to be in nuclear physics, inflation cosmology, geophysics,
and optics (see [1, 2]). Time delays often appear in various
problems, such as thermal, economic, biological, chemical,
and physical phenomena. Recently, partial differential
equations have become an active area with time delay (see
[3, 4]). In 1986, Datko et al. [5] indicated that, in boundary
control, a small delay effect is a source of instability. Gener-
ally, a small delay can destabilize a system which is uniformly
stable [6]. To stabilize hyperbolic systems with time delay,
some control terms will be needed (see [7–9] and references
therein).
For the literature review, firstly, we begin with the studies
of Bialynicki-Birula and Mycielski [10, 11]. The authors
investigated the equation with the logarithmic term as
follows:
u
tt
− u
xx
+ u − εu ln u jj
2
= 0, ð2Þ
where the authors proved that, in any number of dimensions,
wave equations including the logarithmic term have local-
ized, stable, soliton-like solutions.
In 1980, Cazenave and Haraux [12] studied the equation
as follows:
u
tt
− Δu = u ln u jj
k
, ð3Þ
Hindawi
Advances in Mathematical Physics
Volume 2021, Article ID 8561626, 11 pages
https://doi.org/10.1155/2021/8561626