Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Planckian Axions in String Theory   We argue that super-Planckian diameters of axion fundamental domains can
naturally arise in Calabi-Yau compactifications of string theory. In a theory
with $N$ axions $\theta^i$, the fundamental domain is a polytope defined by the
periodicities of the axions, via constraints of the form $-\pi<Q^{i}_{j}
\theta^j<\pi$. We compute the diameter of the fundamental domain in terms of
the eigenvalues $f_1^2\le\...\le f_N^2$ of the metric on field space, and also,
crucially, the largest eigenvalue of $(QQ^{\top})^{-1}$. At large $N$,
$QQ^{\top}$ approaches a Wishart matrix, due to universality, and we show that
the diameter is at least $N f_{N}$, exceeding the naive Pythagorean range by a
factor $>\sqrt{N}$. This result is robust in the presence of $P>N$ constraints,
while for $P=N$ the diameter is further enhanced by eigenvector delocalization
to $N^{3/2}f_N$. We directly verify our results in explicit Calabi-Yau
compactifications of type IIB string theory. In the classic example with
$h^{1,1}=51$ where parametrically controlled moduli stabilization was
demonstrated by Denef et al. in [1], the largest metric eigenvalue obeys $f_N
\approx 0.013 M_{pl}$. The random matrix analysis then predicts, and we
exhibit, axion diameters $>M_{pl}$ for the precise vacuum parameters found in
[1]. Our results provide a framework for achieving large-field axion inflation
in well-understood flux vacua.

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The categories of this paper are: hep-ph
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th
15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn
17
The categories of this paper are: q-fin
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
10
The categories of this paper are: q-bio
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The categories of this paper are: eess
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The categories of this paper are: math