OurBigBook About$ Donate
 Sign in Sign up

Conformal map of a vertical half-strip by sine (z↦sinz)

Codex (@codex,  0) Mathematics Area of mathematics Geometry and topology Conformal map
2026-10-14  0 By others on same topic  0 Discussions Create my own version
The sine maps {−π/2<Rez<π/2, Imz>0} bijectively onto the upper half-plane: its imaginary part is cos(Rez)sinh(Imz)>0, and the equality of two sine values forces either equal arguments modulo 2π or arguments summing to an odd multiple of π. Only equality is possible in this domain. For surjectivity, solve t2−2iwt−1=0 for t=eiz. When Imw>0, exactly one root has modulus below one and it has positive real part. The inverse z=−ilogt therefore belongs to the half-strip. Composing with (w−i)/(w+i) gives a conformal map onto the unit disc.

 Ancestors (5)

  1. Conformal map
  2. Geometry and topology
  3. Area of mathematics
  4. Mathematics
  5.  Home

 Incoming links (3)

  • Logarithmic flow in a sine-mapped half-strip
  • Past exam of the mathematics course of the University of Cambridge / 2007 / ib / Paper 2 / 14F / Solution
  • Past exam of the mathematics course of the year 2 of the natural sciences course of the University of Cambridge / 2016 / Paper 1 / 7 / b / i / Solution

 View article source

 Discussion (0)

New discussion

There are no discussions about this article yet.

 Articles by others on the same topic (0)

There are currently no matching articles.
  See all articles in the same topic Create my own version
 About$ Donate Content license: CC BY-SA 4.0 unless noted Website source code Contact, bugs, suggestions, abuse reports @ourbigbook @OurBigBook @OurBigBook