Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The light curve and the time delay of QSO 0957+561   We present a new analysis of the presently available photometric data for the
gravitationally lensed quasar 0957+561 A,B with the aim of determining the time
delay between its two images. The basic method used is the dispersion
estimation technique. Even by using the simplest non-parametric form of our
method we can convincingly rule out a time delay near 536 days and show that
the time delay is in the vicinity of 420 days. We then introduce refinements to
our method in order to get a stable and reliable result for the time delay
independent of high frequency noise in the data and sampling errors. Our best
result for the time delay, checked by various statistical tests and using
bootstrap error estimates, is 423 +/- 6 days. We furthermore confirm our
earlier result that the radio data are compatible with this value. Using the
best available model for the mass distribution in the lensing galaxy and
cluster, our result for the time delay constrains the Hubble parameter to be
smaller than 70 km/(s Mpc).

25
The categories of this paper are: patt-sol
3
The categories of this paper are: physics
11
The categories of this paper are: hep-lat
4
The categories of this paper are: cond-mat
21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
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The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn
31
The categories of this paper are: ao-sci
5
The categories of this paper are: gr-qc
12
The categories of this paper are: nucl-th
19
The categories of this paper are: eess
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs
2
The categories of this paper are: math