Course home page of
MATH431
(DIFFERENTIAL GEOMETRY)
Winter 2014



1. CURVES IN THE PLANE
  • Lecture Notes
  • HW Assignment no. 1
  • Solutions to HW1
  • click here to see an animation of the cycloid
  • click here to see an animation of the cardioid
  • click here to see an animation of the evolute of the ellipse (which is an astroid)
  • click here to see an animation of the evolute of the tractrix (see question 7, HW1)
  • click here to see a nice Plane Curve Gallery
                                                                                                                                                                                                                       

2. CURVES IN SPACE

3. REGULAR SURFACES

4. LENGTHS AND AREAS ON A SURFACE

5. THE SECOND FUNDAMENTAL FORM OF A SURFACE

6. GAUSS' THEOREMA EGREGIUM


7. GEODESICS AND THE THEOREM OF GAUSS-BONNET


General information

Instructor:       
Dr. Liviu Mare                                                         
Office: CW 307.30       
E-Mail: liviu.mare@gmail.com



                                                           
Lecture Times and Location: Mondays, Wednesdays, and Fridays 11:30 - 12:20, room ED 311

Office hours:
Tuesdays and Thursdays 1:00 - 2:00, or by appointment

Text: lecture notes will be posted regulary on this web site.

Other useful references
Differential Geometry of Curves and Surfaces, by M. P. do Carmo
Modern Differential Geometry of Curves and Surfaces with MATHEMATICA
by A. Gray, E. Abbena, and S. Salamon
Elementary Differential Geometry
by B. O'Neill

Detailed description:
  • curves in the plane (regular curves, examples, curvature, evolutes, involutes, pedal curves, the fundamental theorem of plane curves)
  • curves in space (curvature and torsion, the Frenet formulas, examples, the fundamental theorem of space curves, space curves that lie on a sphere)
  • brief review of vector calculus
  • surfaces in the  space (regular patches, regular surfaces, examples, tangent spaces, surface mappings and tangent maps, level surfaces, examples)
  • orientability of regular surfaces (definition, the Gauss map, examples of non-orientable surfaces)
  • metrics on surfaces (the first fundamental form of a surface, distances and areas on  surfaces, isometries and conformal maps, examples)
  • the shape operator (definition, normal curvature, principal curvature and principal curves, the second fundamental form, the Weingarten equations, Gaussian and mean curvature)
  •  ruled surfaces (definition, examples, curvature calculations)
  •  surfaces of revolution (definition, examples, curvature calculations)
  • Gauss's Theorema Egregium
  • geodesics on surfaces (definition, examples)
  • the Gauss-Bonnet Theorem (local and global versions)
  • minimal surfaces (definition, normal variation, examples, the Gauss map of a minimal surface, isothermal coordinates, the Weierstrass representation, Costa's minimal surface)

Assignments: Sets of assignment questions with prescribed deadlines will be posted on this web page.

Midterm Test: There will be one midterm test written in class.

Final Exam: 
It will be written at the end of the term.

Final Grade: Your final grade will be determined as follows

Assignments
30%
Midterm test
20%
Exam
50%