Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Improved limits for violations of local position invariance from atomic
  clock comparisons   We compare two optical clocks based on the $^2$S$_{1/2}(F=0)\to
{}^2$D$_{3/2}(F=2)$ electric quadrupole (E2) and the $^2$S$_{1/2}(F=0)\to
{}^2$F$_{7/2}(F=3)$ electric octupole (E3) transition of $^{171}$Yb$^{+}$ and
measure the frequency ratio
$\nu_{\mathrm{E3}}/\nu_{\mathrm{E2}}=0.932\,829\,404\,530\,965\,376(32)$. We
determine the transition frequency $\nu_{E3}=642\,121\,496\,772\,645.10(8)$ Hz
using two caesium fountain clocks. Repeated measurements of both quantities
over several years are analyzed for potential violations of local position
invariance. We improve by factors of about 20 and 2 the limits for fractional
temporal variations of the fine structure constant $\alpha$ to
$1.0(1.1)\times10^{-18}/\mathrm{yr}$ and of the proton-to-electron mass ratio
$\mu$ to $-8(36)\times10^{-18}/\mathrm{yr}$. Using the annual variation of the
Sun's gravitational potential at Earth $\Phi$, we improve limits for a
potential coupling of both constants to gravity, $(c^2/\alpha)
(d\alpha/d\Phi)=14(11)\times 10^{-9}$ and $(c^2/\mu) (d\mu/d\Phi)=7(45)\times
10^{-8}$.

30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn
14
The categories of this paper are: math-ph
27
The categories of this paper are: comp-gas
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
17
The categories of this paper are: q-fin
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg