Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Gauge Unification and Flavor Hierarchy from Extra Dimensions   Extra dimension provides an attractive way to break symmetry by boundary
conditions which can be useful to construct a natural grand unified theory
avoiding the doublet-triplet splitting problem and the proton decay problem. It
can provide also an elegant mechanism to generate hierarchical 4-dimensional
Yukawa couplings, involving the quasi-localization of matter fields in extra
dimension. We discuss the Kaluza-Klein threshold corrections to low energy
gauge couplings in generic 5-dimensional orbifold grand unified theories with
quasi-localized matter fields, and apply the results to some class of SU(5)
models on $S^1/Z_2\times Z_2$.

34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th
4
The categories of this paper are: cond-mat
37
The categories of this paper are: supr-con
6
The categories of this paper are: astro-ph
18
The categories of this paper are: econ
29
The categories of this paper are: funct-an
24
The categories of this paper are: dg-ga
25
The categories of this paper are: patt-sol
7
The categories of this paper are: hep-th
14
The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
20
The categories of this paper are: acc-phys
23
The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th