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André Henriques
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Let $U\subset \mathbb R^n$ be an open.

Let $f: S^1 \times U \to \mathbb C$ be a smooth map (i.e. $C^\infty$) s.t. for every $x\in U$ the map $f_x:=f|_{S^1\times \{x\}}:S^1\to \mathbb C$ is a smooth embedding (i.e. with everywhere non-zero derivative) that goes around the origin with winding number $+1$.

For every $x\in U$ there's a unique Riemann map $\Phi_x$ : [unit disc] $\to$ [interior of $f_x(S^1)$] that sends $0\mapsto 0$ and whose derivative at zero is in $\mathbb R_{\ge 0}$.

Is $\Phi:=\coprod_{x\in U}\Phi_x:$ [unit disc] $\times U\to\mathbb C$ smooth?

I'm also interested in the same question where the open unit disc is replaced by the closed unit disc (i.e. smoothness all the way to the boundary).

Let $U\subset \mathbb R^n$ be an open.

Let $f: S^1 \times U \to \mathbb C$ be a smooth map s.t. for every $x\in U$ the map $f_x:=f|_{S^1\times \{x\}}:S^1\to \mathbb C$ is a smooth embedding (i.e. with everywhere non-zero derivative) that goes around the origin with winding number $+1$.

For every $x\in U$ there's a unique Riemann map $\Phi_x$ : [unit disc] $\to$ [interior of $f_x(S^1)$] that sends $0\mapsto 0$ and whose derivative at zero is in $\mathbb R_{\ge 0}$.

Is $\Phi:=\coprod_{x\in U}\Phi_x:$ [unit disc] $\times U\to\mathbb C$ smooth?

I'm also interested in the same question where the open unit disc is replaced by the closed unit disc (i.e. smoothness all the way to the boundary).

Let $U\subset \mathbb R^n$ be an open.

Let $f: S^1 \times U \to \mathbb C$ be a smooth map (i.e. $C^\infty$) s.t. for every $x\in U$ the map $f_x:=f|_{S^1\times \{x\}}:S^1\to \mathbb C$ is a smooth embedding (i.e. with everywhere non-zero derivative) that goes around the origin with winding number $+1$.

For every $x\in U$ there's a unique Riemann map $\Phi_x$ : [unit disc] $\to$ [interior of $f_x(S^1)$] that sends $0\mapsto 0$ and whose derivative at zero is in $\mathbb R_{\ge 0}$.

Is $\Phi:=\coprod_{x\in U}\Phi_x:$ [unit disc] $\times U\to\mathbb C$ smooth?

I'm also interested in the same question where the open unit disc is replaced by the closed unit disc (i.e. smoothness all the way to the boundary).

added 49 characters in body
Source Link
André Henriques
  • 43.2k
  • 5
  • 130
  • 264

Let $U\subset \mathbb R^n$ be an open.

Let $f: S^1 \times U \to \mathbb C$ be a smooth map s.t. for every $x\in U$ the map $f_x:=f|_{S^1\times \{x\}}:S^1\to \mathbb C$ is ana smooth embedding (i.e. with everywhere non-zero derivative) that goes around the origin with winding number $+1$.

For every $x\in U$ there's a unique Riemann map $\Phi_x$ : [unit disc] $\to$ [interior of $f_x(S^1)$] that sends $0\mapsto 0$ and whose derivative at zero is in $\mathbb R_{\ge 0}$.

Is $\Phi:=\coprod_{x\in U}\Phi_x:$ [unit disc] $\times U\to\mathbb C$ smooth?

I'm also interested in the same question where the open unit disc is replaced by the closed unit disc (i.e. smoothness all the way to the boundary).

Let $U\subset \mathbb R^n$ be an open.

Let $f: S^1 \times U \to \mathbb C$ be a smooth map s.t. for every $x\in U$ the map $f_x:=f|_{S^1\times \{x\}}:S^1\to \mathbb C$ is an embedding that goes around the origin with winding number $+1$.

For every $x\in U$ there's a unique Riemann map $\Phi_x$ : [unit disc] $\to$ [interior of $f_x(S^1)$] that sends $0\mapsto 0$ and whose derivative at zero is in $\mathbb R_{\ge 0}$.

Is $\Phi:=\coprod_{x\in U}\Phi_x:$ [unit disc] $\times U\to\mathbb C$ smooth?

I'm also interested in the same question where the open unit disc is replaced by the closed unit disc (i.e. smoothness all the way to the boundary).

Let $U\subset \mathbb R^n$ be an open.

Let $f: S^1 \times U \to \mathbb C$ be a smooth map s.t. for every $x\in U$ the map $f_x:=f|_{S^1\times \{x\}}:S^1\to \mathbb C$ is a smooth embedding (i.e. with everywhere non-zero derivative) that goes around the origin with winding number $+1$.

For every $x\in U$ there's a unique Riemann map $\Phi_x$ : [unit disc] $\to$ [interior of $f_x(S^1)$] that sends $0\mapsto 0$ and whose derivative at zero is in $\mathbb R_{\ge 0}$.

Is $\Phi:=\coprod_{x\in U}\Phi_x:$ [unit disc] $\times U\to\mathbb C$ smooth?

I'm also interested in the same question where the open unit disc is replaced by the closed unit disc (i.e. smoothness all the way to the boundary).

Source Link
André Henriques
  • 43.2k
  • 5
  • 130
  • 264

families of Riemann mappings

Let $U\subset \mathbb R^n$ be an open.

Let $f: S^1 \times U \to \mathbb C$ be a smooth map s.t. for every $x\in U$ the map $f_x:=f|_{S^1\times \{x\}}:S^1\to \mathbb C$ is an embedding that goes around the origin with winding number $+1$.

For every $x\in U$ there's a unique Riemann map $\Phi_x$ : [unit disc] $\to$ [interior of $f_x(S^1)$] that sends $0\mapsto 0$ and whose derivative at zero is in $\mathbb R_{\ge 0}$.

Is $\Phi:=\coprod_{x\in U}\Phi_x:$ [unit disc] $\times U\to\mathbb C$ smooth?

I'm also interested in the same question where the open unit disc is replaced by the closed unit disc (i.e. smoothness all the way to the boundary).