Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Various variational approximations of quantum dynamics   We investigate variational principles for the approximation of quantum
dynamics that apply for approximation manifolds that do not have complex linear
tangent spaces. The first one, dating back to McLachlan (1964) minimizes the
residuum of the time-dependent Schr\"odinger equation, while the second one,
originating from the lecture notes of Kramer--Saraceno (1981), imposes the
stationarity of an action functional. We characterize both principles in terms
of metric and a symplectic orthogonality conditions, consider their
conservation properties, and derive an elementary a-posteriori error estimate.
As an application, we revisit the time-dependent Hartree approximation and
frozen Gaussian wave packets.

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The categories of this paper are: econ
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
32
The categories of this paper are: atom-ph
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The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
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The categories of this paper are: astro-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: hep-th
4
The categories of this paper are: cond-mat
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The categories of this paper are: funct-an
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The categories of this paper are: chem-ph
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The categories of this paper are: adap-org
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The categories of this paper are: plasm-ph
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The categories of this paper are: mtrl-th
11
The categories of this paper are: hep-lat