Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Branes and the Gauge Hierarchy   If the fundamental type-I string scale is of the order of few TeV, the
problem of the gauge hierarchy is that of understanding why some dimensions
transverse to our brane-world are so large. The technical aspect of this
problem, as usually formulated, is `why quantum corrections do not modify
drastically the masses and other parameters of the Standard Model'. We argue
that within type-I perturbation theory, the technical hierarchy problem is
solved (a) if all massless tadpoles cancel locally over distances of order the
string length in the transverse space, or (b) if the massless fields with
uncancelled local tadpoles propagate `effectively' in $d_\perp \ge 2$ large
transverse dimensions. These restrictions ensure that loop corrections to the
Standard Model parameters decouple from the four-dimensional Planck scale,
except when there are uncancelled tadpoles in $d_\perp =2$ in which case the
dependence on $M_P$ is logarithmic. This latter case is thus singled out as the
only one in which the origin of the hierarchy would not be attributed entirely
to `out of this world' bulk physics. The role of the renormalization group
equations in summing the leading large logs is replaced by the classical 2d
supergravity equations in the transverse space.

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The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
27
The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph
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The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
3
The categories of this paper are: physics
26
The categories of this paper are: bayes-an