diff --git a/images/RibbonUnknot.jpg b/images/RibbonUnknot.jpg new file mode 100644 index 0000000..5e56147 Binary files /dev/null and b/images/RibbonUnknot.jpg differ diff --git a/images/TwistedUnknot.jpg b/images/TwistedUnknot.jpg new file mode 100644 index 0000000..6a04e6c Binary files /dev/null and b/images/TwistedUnknot.jpg differ diff --git a/images/Twminus.jpg b/images/Twminus.jpg new file mode 100644 index 0000000..5f9d8b1 Binary files /dev/null and b/images/Twminus.jpg differ diff --git a/images/Twplus.jpg b/images/Twplus.jpg new file mode 100644 index 0000000..10e035e Binary files /dev/null and b/images/Twplus.jpg differ diff --git a/images/moves.png b/images/moves.png new file mode 100644 index 0000000..557d65a Binary files /dev/null and b/images/moves.png differ diff --git a/lectures_on_knot_theory.tex b/lectures_on_knot_theory.tex new file mode 100644 index 0000000..8727e23 --- /dev/null +++ b/lectures_on_knot_theory.tex @@ -0,0 +1,119 @@ +\documentclass[12pt, twoside]{article} + +\usepackage{comment} +\usepackage{amssymb} +\usepackage{amsmath} +\usepackage[english]{babel} +\usepackage{csquotes} +\usepackage{graphicx} +\usepackage{float} +\usepackage{titlesec} +\usepackage{comment} +\usepackage{pict2e} + +\usepackage{advdate} + +%... Set the first lecture date +\ThisYear{2019} +\ThisMonth{3} +\ThisDay{5} + + +\graphicspath{ {images/} } + +\newtheorem{lemama}{Lemma} +\newtheorem{fact}{Fact} +\newtheorem{example}{Example} +%\theoremstyle{definition} +\newtheorem{definition}{Definition} +%\theoremstyle{plain} +\newtheorem{theorem}{Theorem} +\newtheorem{proposition}{Proposition} + +\input{knots_macros} + + +\titleformat{\section}{\normalfont \Large \bfseries} +{Lecture\ \thesection}{2.3ex plus .2ex}{} +\titlespacing{\subsection}{2em}{*1}{*1} + + +\begin{document} +%\input{myNotes} + +\section{} +\begin{definition} +A \textbf{knot} $K$ in $S^3$ is a smooth (PL - smooth) embedding of a circle $S^1$ in $S^3$: +\begin{align*} +\varphi: S^1 \hookrightarrow S^3 +\end{align*} +\end{definition} +Usually we think about a knot as an image of an embedding: $K = \varphi(S^1)$. +\begin{definition} +\hfill\\ +Two knots $K_0 = \varphi_0(S^1)$, $K_1 = \varphi_1(S^1)$ are equivalent if the embeddings $\varphi_0$ and $\varphi_1$ are isotopic, that is there exists a continues function +\begin{align*} +&\Phi: S^1 \times [0, 1] \hookrightarrow S^3 \\ +&\Phi(x, t) = \Phi_t(x) +\end{align*} + such that $\Phi_t$ is an embedding for any $t \in [0,1]$, $\Phi_0 = \varphi_0$ and +$\Phi_1 = \varphi_1$ +\\ +Two knots $K_0$ and $K_1$ are isotopic if and only if they are ambient isotopic, i.e. there exists a family of self-diffeomorphisms $\Phi$ such that: +\begin{align*} +&\Psi: S^3 \hookrightarrow S^3\\ +& \psi_0 = id\\ +& \psi_1(K_0) = K_1 +\end{align*} +\end{definition} +\begin{definition} +A knot is trivial (unknot) if it is equivalent to an embedding $\varphi(t) = (\cos t, \sin t, 0)$, where $t \in [0, 2 \pi] $ is a parametrisation of $S^1$. +\end{definition} +\begin{definition} +A link with k - components is a (smooth) embedding of\\ $\overbrace{S^1 \sqcup \ldots \sqcup S^1}^k$ in $S^3$ +\end{definition} +\begin{example} +A trivial link with $3$ components\\ +A hopf link\\ +Whitehead link\\ +Borromean link +\end{example} +\begin{definition} +A link diagram is a picture over projection of a link is $S^3$/$R^3$ such that: +\begin{enumerate} +\item is non degenerate +\item The double points are not degenerated +\item There are no triple point +\end{enumerate} +\end{definition} +There are under- and overcrossings (tunnels and bridges) on a link diagrams with an obvious meaning.\\ +Every link admits a link diagram. + +\subsection{Reidemeister moves} +A Reidemeister move is one of the three types of operation on a link diagram as shown in Figure~\ref{fig: reidemeister}. +% +The first Reidemeister move inserts or removes a coil. +% +The second Reidemeister move slides a strand and inserts or removes two crossings of opposite sign. +% +The third Reidemeister move slides a strand over or under a crossing. +\begin{figure}[H] +\centering +\includegraphics[width=0.7\textwidth]{moves.png} +\caption{\label{fig: reidemeister}Reidemeister moves (adapted from Adams).} +\end{figure} +\begin{theorem} [Reidemeister’s Theorem] +Two diagrams of the same link can be +deformed into each other by a finite sequence of Reidemeister moves (and isotopy of the plane). +\end{theorem} +\section{Z nagrania Kamili} +\begin{example} +\begin{align*} +&F: \mathbb{C}^2 \rightarrow \mathbb{C} \text{a polynomial} \\ +&F(0) = 0 +\end{align*} +Fact (Milnor Singular Points of Complex Hypersurfaces): +\end{example} +\section{} 25.03.19 + +\end{document} \ No newline at end of file