Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Twice regularized MDPs and the equivalence between robustness and
  regularization   Robust Markov decision processes (MDPs) aim to handle changing or partially
known system dynamics. To solve them, one typically resorts to robust
optimization methods. However, this significantly increases computational
complexity and limits scalability in both learning and planning. On the other
hand, regularized MDPs show more stability in policy learning without impairing
time complexity. Yet, they generally do not encompass uncertainty in the model
dynamics. In this work, we aim to learn robust MDPs using regularization. We
first show that regularized MDPs are a particular instance of robust MDPs with
uncertain reward. We thus establish that policy iteration on reward-robust MDPs
can have the same time complexity as on regularized MDPs. We further extend
this relationship to MDPs with uncertain transitions: this leads to a
regularization term with an additional dependence on the value function. We
finally generalize regularized MDPs to twice regularized MDPs (R${}^2$ MDPs),
i.e., MDPs with $\textit{both}$ value and policy regularization. The
corresponding Bellman operators enable developing policy iteration schemes with
convergence and robustness guarantees. It also reduces planning and learning in
robust MDPs to regularized MDPs.

7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
31
The categories of this paper are: ao-sci
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
6
The categories of this paper are: astro-ph
8
The categories of this paper are: hep-ex
34
The categories of this paper are: chem-ph
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
4
The categories of this paper are: cond-mat