Show that a nonnegative harmonic function is constant
88790
Positive harmonic function on $\mathbb{R}^n$ is a constant?
20415
Show that the integral of a positive function is positive
137043
To show that function is constant
13755
Is there a harmonic function in the whole plane that is postive everywhere?
142494
Functions $f(x)/g(x), g(x)/h(x),h(x)/f(x)$ are constant
35787
An entire function with a bound on its integral is constant
31672
$L^p$-norm of the gradient of a harmonic function.
112211
Show an increasing function f from omega_1 to R is eventually constant
18207
Removable singularity for harmonic functions
100608
Prove that $\|v\|_{H^1(\Omega )}\leq C(\|f\|_{L^2(\Omega )}+\|v\|_{H^{1/2}(\partial \Omega )}+\|\partial _\nu v\|_{H^{1/2}(\partial \Omega )}))$
48314
Show that if a function is not negative and its integral is $0$ than the function is $0$
158407
derivative bounded by a constant multiple of the function
9159
$L^p$-norm of a non-negative measurable function
7878
Proving that a doubly-periodic entire function $f$ is constant.
149564
Showing that a function is in $L^1$
82001
How to prove the function is a constant
5416
How does one prove if a multivariate function is constant?