Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Universe at Extreme Scale: Multi-Petaflop Sky Simulation on the BG/Q   Remarkable observational advances have established a compelling
cross-validated model of the Universe. Yet, two key pillars of this model --
dark matter and dark energy -- remain mysterious. Sky surveys that map billions
of galaxies to explore the `Dark Universe', demand a corresponding
extreme-scale simulation capability; the HACC (Hybrid/Hardware Accelerated
Cosmology Code) framework has been designed to deliver this level of
performance now, and into the future. With its novel algorithmic structure,
HACC allows flexible tuning across diverse architectures, including accelerated
and multi-core systems.
  On the IBM BG/Q, HACC attains unprecedented scalable performance -- currently
13.94 PFlops at 69.2% of peak and 90% parallel efficiency on 1,572,864 cores
with an equal number of MPI ranks, and a concurrency of 6.3 million. This level
of performance was achieved at extreme problem sizes, including a benchmark run
with more than 3.6 trillion particles, significantly larger than any
cosmological simulation yet performed.

20
The categories of this paper are: acc-phys
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol
14
The categories of this paper are: math-ph
0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph
37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
23
The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org