Math 164H Schedule


MondayWednesdayFriday
August 21

Syllabus
August 23

What is a knot?
August 25

Unknotting number
August 28

Unknotting number
August 30

Unknotting number
September 1

Composition of knots
September 4
No Class - Labor Day
September 6

Reidemeister moves
September 8

Semester project assigned
Tricoloration
September 11

More on tricoloration
Modular arithmetic
September 13

Modular arithmetic
p-colorations
September 15

More on p-coloration
September 18

Dowker notation
September 20

Dowker notation
September 22

Dowker notation
September 25

More on Dowker notation
September 27

More on Dowker notation
September 29


Conway notation
October 2

Conway notation
October 4

Exercise 2.13
Tangles for your knots
October 6

Tangles
October 9

Tangles
October 11

Review for exam
October 13
Exam
October 16

Rational knots and unknotting number
October 18

October 20

No class
October 23

Mathematically celtic knots
October 25

Mathematically celtic knots
October 27

Bridge number
October 30

Bridge number
2-Bridge knots are rational
November 1

Alexander polynomial
November 3

November 6

November 8

November 10

November 13

November 15

November 17

November 20

Projects Due
Thanksgiving Break
No Classes
November 27

November 29

December 1

December 4

December 6

Review
 

August 21


Topics CoveredHomework
Syllabus


Get book
Pick your pet knot
Come on Wednesday ready to work

August 23


Topics CoveredHomework
What is a knot?
What is a link?
Crossings in a projection
Crossing number of a knot
Knots of crossing number 0
Knots of crossing number 1
Knots of crossing number 2
Amphichiral knots


Identify the 4 crossing knot drawn in class
Identify the monster - which knot is it?
Do exercise 1.3

August 25


Topics CoveredHomework
The 4 crossing knot drawn in class was the trefoil!
The monster was the unknot!
Any knot has a projection with 1000 crossings!
Alternating knots
Changing crossings to get to the unknot
Unknotting number


Find the unknotting number of your knot.
Why can every knot be made into the unknot by changing some number of crossings?

August 28


Topics CoveredHomework
unknotting numbers of everyone's pet knots

Find the unknotting number of the 8_18 knot
Find a knot whose unknotting number is unknown
Exercise 1.6
Exercise 1.7 - Why can every knot be made into the unknot by changing some number of crossings?

August 30


Topics CoveredHomework
Unknotting numbers of 8_18
Knots with unknown unknotting number
See this page to see that the 8_10, 9_10, 9_13, 9_29, and other knots have unknown unknotting numbers

See this page for one example of a knot whose minimal crossing projection does not have the minimal unknotting number

Why can every knot be unknotted?


Read Section 1.2

September 1


Topics CoveredHomework
unknotting number revisited one last time

prime numbers
Ccomposite numbers

composite knots
prime knots
numbers of prime knots


Find u(8_19)
Read the article

September 6


Topics CoveredHomework
u(8_19)
Reidemeister moves


Find a sequence of R-moves to change the picture in class into its standard presentation
Read the article

September 8


Topics CoveredHomework
Tricoloration
It is invariant under Reidemeister moves


Is your knot tricolorable?
Finish checking that tricoloration is invariant under Reidemeister moves
Read the article

September 11


Topics CoveredHomework
Whose knots are Tricolorable?
It is invariant under Reidemeister moves
Modular arithmetic
cAdding in different bases


Finish checking that tricoloration is invariant under Reidemeister moves
Read the article

September 13


Topics CoveredHomework
Modular arithmetic
p-coloration
The 4_1 knot is 5-colorable
The unknot is not 5-colorable
The 4_1 is not the unknot


Is the monster 5-colorable?
(For Monday) Find a prime p (other than 3) so that your knot is p-colorable
Read the article

September 15


Topics CoveredHomework
p-coloration
If a knot has a 3-coloration, must it have a 5-coloration?
If a knot has a p-coloration, must it have a np-coloration?


Find a prime p (other than 3) so that your knot is p-colorable
Read the article

September 18


Topics CoveredHomework
Dowker notation
Calculating Dowker notation
Recreating a knot from Dowker notation


Find a prime p (other than 3) so that your knot is p-colorable
Find a non-prime (other than a multiple of 3) so that your knot is p-colorable
(For Fri) Find all possible Dowker notations for your knot
Read the article

September 20


Topics CoveredHomework
Dowker notation
Calculating Dowker notation
Recreating a knot from Dowker notation
Dowker notation for alternating knots


Find a prime p (other than 3) so that your knot is p-colorable
Find a non-prime (other than a multiple of 3) so that your knot is p-colorable
(For Fri) Find all possible Dowker notations for your knot
Exercise 2.9
Read the article

September 22


Topics CoveredHomework
How to tell when Dowker notation indicates an Reidemeister Type 1 move


Find a prime p (other than 3) so that your knot is p-colorable
Find a non-prime (other than a multiple of 3) so that your knot is p-colorable
Finish Excercise 2.9
Read the article

September 25


Topics CoveredHomework
How to tell when Dowker notation indicates an Reidemeister Type 2 move


Find a prime p (other than 3) so that your knot is p-colorable
Find a non-prime (other than a multiple of 3) so that your knot is p-colorable
Write a random string of Dowker notations and determine if it represents a Type 1 or Type 2 move
Read the article

September 27


Topics CoveredHomework
How to tell when Dowker notation indicates an Reidemeister Type 2 move
Testing Josh's conjectures


Find a prime p (other than 3) so that your knot is p-colorable
Find a non-prime (other than a multiple of 3) so that your knot is p-colorable
Write a random string of Dowker notations and determine if it represents a Type 1 or Type 2 move
Read the article

September 29


Topics CoveredHomework
Conway Notation


Do exercise 2.11
determine the conway notation for your knot (if it has one)
Read the article

October 2


Topics CoveredHomework
Conway Notation
Discuss exercise 2.11
Continued fractions


Do exercise 2.13
determine the conway notation for your knot (if it has one)
Read the article

October 4


Topics CoveredHomework
Discuss exercise 2.13
Discuss rational tangle notation for your knots


determine the conway notation for your knot (if it has one)
Read the article

October 16


Topics CoveredHomework
Rational tangles and their unknotting numbers - see page 62


Determine the unknotting number of the presentation 2 -2 2 -2 2 4
Read the article

October 23


Topics CoveredHomework
Mathematically celtic knots

Determine whether your knot is mathematically celtic.
Read the article

October 25


Topics CoveredHomework
Mathematically celtic knots, again

Write up whether your knot is mathematically celtic.
Are all alternating knots mathematically celtic?
Read the article