For an open set $$\Omega \subset \mathbb {R}^2$$
Ω
⊂
R
2
let $$\lambda (\Omega )$$
λ
(
Ω
)
denote the bottom of the spectrum of the Dirichlet Laplacian acting in $$L^2(\Omega )$$
L
2
(
Ω
)
. Let $$w_\Omega $$
w
Ω
be the torsion function for $$\Omega $$
Ω
, and let $$\Vert .\Vert _p$$
‖
.
‖
p
denote the $$L^p$$
L
p
norm. It is shown that there exist $$\eta _1>0,\eta _2>0$$
η
1
>
0
,
η
2
>
0
such that (i) $$\Vert w_{\Omega }\Vert _{\infty } \lambda (\Omega )\ge 1+\eta _1$$
‖
w
Ω
‖
∞
λ
(
Ω
)
≥
1
+
η
1
for any non-empty, open, simply connected set $$\Omega \subset \mathbb {R}^2$$
Ω
⊂
R
2
with $$\lambda (\Omega ) >0$$
λ
(
Ω
)
>
0
, (ii) $$\Vert w_{\Omega }\Vert _1\lambda (\Omega )\le {(1-\eta _2)}|\Omega |$$
‖
w
Ω
‖
1
λ
(
Ω
)
≤
(
1
-
η
2
)
|
Ω
|
for any non-empty, open, simply connected set $$\Omega \subset \mathbb {R}^2$$
Ω
⊂
R
2
with finite measure $$|\Omega |$$
|
Ω
|
.