\( \def\CC{{\mathbb C}} \def\RR{{\mathbb R}} \def\NN{{\mathbb N}} \def\ZZ{{\mathbb Z}} \def\TT{{\mathbb T}} \def\CF{{\operatorname{CF}^\bullet}} \def\HF{{\operatorname{HF}^\bullet}} \def\SH{{\operatorname{SH}^\bullet}} \def\ot{{\leftarrow}} \def\st{\;:\;} \def\Fuk{{\operatorname{Fuk}}} \def\emprod{m} \def\cone{\operatorname{Cone}} \def\Flux{\operatorname{Flux}} \def\li{i} \def\ev{\operatorname{ev}} \def\id{\operatorname{id}} \def\grad{\operatorname{grad}} \def\ind{\operatorname{ind}} \def\weight{\operatorname{wt}} \def\Sym{\operatorname{Sym}} \def\HeF{\widehat{CHF}^\bullet} \def\HHeF{\widehat{HHF}^\bullet} \def\Spinc{\operatorname{Spin}^c} \def\min{\operatorname{min}} \def\div{\operatorname{div}} \def\SH{{\operatorname{SH}^\bullet}} \def\CF{{\operatorname{CF}^\bullet}} \def\Tw{{\operatorname{Tw}}} \def\Log{{\operatorname{Log}}} \def\TropB{{\operatorname{TropB}}} \def\wt{{\operatorname{wt}}} \def\Span{{\operatorname{span}}} \def\Crit{\operatorname{Crit}} \def\CritVal{\operatorname{CritVal}} \def\FS{\operatorname{FS}} \def\Sing{\operatorname{Sing}} \def\Coh{\operatorname{Coh}} \def\Vect{\operatorname{Vect}} \def\into{\hookrightarrow} \def\tensor{\otimes} \def\CP{\mathbb{CP}} \def\eps{\varepsilon} \) SympSnip:

Observe that the level sets of a linear Hamiltonian are \(\{r\}\times M\). The Hamiltonian vector field therefore can be restricted to a vector field on the contact manifold \(M\). It is not a surprise that the \(m V_\alpha\) and Hamiltonian vector field \(H_V\) agree: \begin{align*} \iota_{i_* m V_\alpha}\omega=& d(\exp(r) \alpha )(m V_\alpha)\\ =&(\exp(r) dr \wedge d\alpha - \exp(r) d\alpha) (m V_\alpha)\\ =&- m \cdot \exp(r)dr = dH^m \end{align*} Therefore, the time one Hamiltonian orbits of \(H^m\) correspond to the time \(m\) Reeb orbits of \(V_\alpha\); by studying Hamiltonian Floer theory on the symplectization \(\RR\times M\) we obtain some understanding of the Reeb dynamics of \((M, \alpha)\). A useful observation is the following: suppose that \(m\) is not a period of some Reeb orbit. Then \(\RR\times M\) has no time one orbits for the linear Hamiltonian of slope \(m\).