1,452 research outputs found
Towards Physical Understanding of Galaxy-Halo Alignment
We investigate the alignment of galaxy and halo orientations using the
TNG300-1 hydrodynamical simulation. Our analysis reveals that the distribution
of the 2D misalignment angle can be well described by a
truncated shifted exponential (TSE) distribution with only {\textit{one}} free
parameter across different redshifts and galaxy/halo properties. We demonstrate
that the galaxy-ellipticity (GI) correlations of galaxies can be reproduced by
perturbing halo orientations with the obtained distribution,
with only a small bias () possibly arising from unaccounted
couplings between and other factors. We find that both the
2D and 3D misalignment angles and
decrease with ex situ stellar mass fraction , halo mass
and stellar mass , while increasing with disk-to-total
stellar mass fraction and redshift. These dependences are in
good agreement with our recent observational study based on the BOSS galaxy
samples. Our results suggest that is a key factor in determining
the galaxy-halo alignment. Grouping galaxies by nearly
eliminates the dependence of on for all three
principle axes, and also reduces the redshift dependence. For
, we find a more significant redshift dependence than for
even after controlling , which may be
attributed to the evolution of galaxy and halo shapes. Our findings present a
valuable model for observational studies and enhance our understanding of
galaxy-halo alignment.Comment: 19 pages, 12 figures, submitted to Ap
Retrieving non-linear features from noisy quantum states
Accurately estimating high-order moments of quantum states is an elementary
precondition for many crucial tasks in quantum computing, such as entanglement
spectroscopy, entropy estimation, spectrum estimation and predicting non-linear
features from quantum states. But in reality, inevitable quantum noise prevents
us from accessing the desired value. In this paper, we address this issue by
systematically analyzing the feasibility and efficiency of extracting
high-order moments from noisy states. We first show that there exists a quantum
protocol capable of accomplishing this task if and only if the underlying noise
channel is invertible. We then establish a method for deriving protocols that
attain optimal sample complexity using quantum operations and classical
post-processing only. Our protocols, in contrast to conventional ones, incur
lower overheads and avoid sampling different quantum operations due to a novel
technique called observable shift, making the protocols strong candidates for
practical usage on current quantum devices. The proposed method also indicates
the power of entangled protocols in retrieving high-order information, whereas
in the existing methods, entanglement does not help. Our work contributes to a
deeper understanding of how quantum noise could affect high-order information
extraction and provides guidance on how to tackle it.Comment: 23 pages, 6 figure
Evidence for baryon acoustic oscillations from galaxy-ellipticity correlations
The Baryon Acoustic Oscillations (BAO) feature in the clustering of galaxies
or quasars provides a ``standard ruler" for distance measurements in cosmology.
In this work, we report a signal of the BAO dip feature in the
galaxy density-ellipticity (GI) cross-correlation functions using the
spectroscopic sample of the Baryon Oscillation Spectroscopic Survey (BOSS)
CMASS, combined with the deep DESI Legacy Imaging Surveys for precise galaxy
shape measurements. We measure the GI correlation functions and model them
using the linear alignment model. We constrain the distance
to redshift to a precision of , depending
on the details of modeling. The GI measurement reduces the uncertainty of
distance measurement by on top of that derived from the
galaxy-galaxy (GG) correlation. More importantly, for future large and deep
galaxy surveys, the independent GI measurements can help sort out the
systematics in the BAO studies.Comment: Main text 3 figures + supplementary 5 figures. Published in Nature
Astronom
Evaluating and Improving Tool-Augmented Computation-Intensive Math Reasoning
Chain-of-thought prompting~(CoT) and tool augmentation have been validated in
recent work as effective practices for improving large language models~(LLMs)
to perform step-by-step reasoning on complex math-related tasks. However, most
existing math reasoning datasets may be not able to fully evaluate and analyze
the ability of LLMs in manipulating tools and performing reasoning, as they may
only require very few invocations of tools or miss annotations for evaluating
intermediate reasoning steps. To address the issue, we construct \textbf{CARP},
a new Chinese dataset consisting of 4,886 computation-intensive algebra
problems with formulated annotations on intermediate steps. In CARP, we test
four LLMs with CoT prompting, and find that they are all prone to make mistakes
at the early steps of the solution, leading to wrong answers. Based on this
finding, we propose a new approach that can deliberate the reasoning steps with
tool interfaces, namely \textbf{DELI}. In DELI, we first initialize a
step-by-step solution based on retrieved exemplars, then iterate two
deliberation procedures that check and refine the intermediate steps of the
generated solution, from the perspectives of tool manipulation and natural
language reasoning, until obtaining converged solutions or reaching the maximum
turn. Experimental results on CARP and six other datasets show that the
proposed DELI mostly outperforms competitive baselines, and can further boost
the performance of existing CoT methods. Our data and code are available in
\url{https://github.com/RUCAIBox/CARP}.Comment: 17 pages, working in progres
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