Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Linking/$S^1$ Equivariant Variational Argument in the space of Dual
  Legendrian curves and the proof of the Weinstein Conjecture on $S^3$ "in the
  large"   Let $\alpha$ be a contact form on $S^3$, let $\xi$ be its Reeb vector-field
and let $v$ be a non-singular vector-field in $ker\alpha$. Let $C_\beta$ be the
space of curves $x$ on $S^3$ such $\dot x=a\xi+bv, \dot a=0, a \gneq 0$. Let
$L^+$, respectively $L^-$, be the set of curves in $C_\beta$ such that $b\geq
0$, respectively $b \leq 0$. Let, for $x \in C_\beta$,
$J(x)=\int_0^1\alpha_x(\dot x)dt$. We establish in this paper that an infinite
number of cycles in the $S^1$-equivariant homology of $C_\beta$,{\bf relative}
to $L^+ \cup L^-$ and to some specially designed "bottom set", see section 4,
are achieved in the Morse complex of $(J, C_\beta)$ by unions of unstable
manifolds of critical points (at infinity)which must include periodic orbits of
$\xi$; ie unions of unstable manifolds of critical points at infinity alone
cannot achieve these cycles. The topological argument of existence of a
periodic orbit for $\xi$ turns out to be surprisingly close, in spirit, to the
linking/equivariant argument of P.H. Rabinowitz in [12]. The objects and the
frameworks are strikingly different, but the original proof of [12] can be
recognized in our proof, which uses degree theory, the Fadell-Rabinowitz index
[8] and the fact that $\pi_{n+1}(S^n)=\mathbb{Z}_2, n\geq 3$. The arguments
hold under the basic assumption that no periodic orbit of index $1$ connects
$L^+$ and $L^-$. To a certain extent, the present result runs, especially in
the case of three-dimensional overtwisted [8] contact forms, against the
existence of non-trivial algebraic invariants defined by the periodic orbits of
$\xi$ and independent of what $ker \alpha$ and/or $\alpha$ are.

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The categories of this paper are: q-alg
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The categories of this paper are: chao-dyn
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The categories of this paper are: funct-an
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The categories of this paper are: math-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: alg-geom
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The categories of this paper are: supr-con
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The categories of this paper are: physics
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The categories of this paper are: bayes-an
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The categories of this paper are: cmp-lg
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The categories of this paper are: nucl-th
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The categories of this paper are: cond-mat
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The categories of this paper are: q-fin
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The categories of this paper are: nlin
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The categories of this paper are: hep-lat