180 research outputs found
Einstein Finsler Metrics and Killing Vector Fields on Riemannian Manifolds
In this paper, we use a Killing form on a Riemannian manifold to construct a
class of Finsler metrics. We find equations that characterize Einstein metrics
among this class. In particular, we construct a family of Einstein metrics on
with , and ,
respectively. This family of metrics provide an important class of Finsler
metrics in dimension three, whose Ricci curvature is a constant, but the flag
curvature is not
On the flag curvature of Finsler metrics of scalar curvature
The flag curvature of a Finsler metric is called a Riemannian quantity
because it is an extension of sectional curvature in Riemannian geometry. In
Finsler geometry, there are several non-Riemannian quantities such as the
(mean) Cartan torsion, the (mean) Landsberg curvature and the S-curvature,
which all vanish for Riemannian metrics. It is important to understand the
geometric meanings of these quantities. In this paper, we study Finsler metrics
of scalar curvature (i.e., the flag curvature is a scalar function on the slit
tangent bundle) and partially determine the flag curvature when certain
non-Riemannian quantities are isotropic. Using the obtained formula for the
flag curvature, we classify locally projectively flat Randers metrics with
isotropic S-curvature.Comment: 23 page
"Do Anything Now": Characterizing and Evaluating In-The-Wild Jailbreak Prompts on Large Language Models
The misuse of large language models (LLMs) has garnered significant attention
from the general public and LLM vendors. In response, efforts have been made to
align LLMs with human values and intent use. However, a particular type of
adversarial prompts, known as jailbreak prompt, has emerged and continuously
evolved to bypass the safeguards and elicit harmful content from LLMs. In this
paper, we conduct the first measurement study on jailbreak prompts in the wild,
with 6,387 prompts collected from four platforms over six months. Leveraging
natural language processing technologies and graph-based community detection
methods, we discover unique characteristics of jailbreak prompts and their
major attack strategies, such as prompt injection and privilege escalation. We
also observe that jailbreak prompts increasingly shift from public platforms to
private ones, posing new challenges for LLM vendors in proactive detection. To
assess the potential harm caused by jailbreak prompts, we create a question set
comprising 46,800 samples across 13 forbidden scenarios. Our experiments show
that current LLMs and safeguards cannot adequately defend jailbreak prompts in
all scenarios. Particularly, we identify two highly effective jailbreak prompts
which achieve 0.99 attack success rates on ChatGPT (GPT-3.5) and GPT-4, and
they have persisted online for over 100 days. Our work sheds light on the
severe and evolving threat landscape of jailbreak prompts. We hope our study
can facilitate the research community and LLM vendors in promoting safer and
regulated LLMs
Confidence bands for a log-concave density
We present a new approach for inference about a log-concave distribution:
Instead of using the method of maximum likelihood, we propose to incorporate
the log-concavity constraint in an appropriate nonparametric confidence set for
the cdf . This approach has the advantage that it automatically provides a
measure of statistical uncertainty and it thus overcomes a marked limitation of
the maximum likelihood estimate. In particular, we show how to construct
confidence bands for the density that have a finite sample guaranteed
confidence level. The nonparametric confidence set for which we introduce
here has attractive computational and statistical properties: It allows to
bring modern tools from optimization to bear on this problem via difference of
convex programming, and it results in optimal statistical inference. We show
that the width of the resulting confidence bands converges at nearly the
parametric rate when the log density is -affine.Comment: Added more experiments, other minor change
In ChatGPT We Trust? Measuring and Characterizing the Reliability of ChatGPT
The way users acquire information is undergoing a paradigm shift with the
advent of ChatGPT. Unlike conventional search engines, ChatGPT retrieves
knowledge from the model itself and generates answers for users. ChatGPT's
impressive question-answering (QA) capability has attracted more than 100
million users within a short period of time but has also raised concerns
regarding its reliability. In this paper, we perform the first large-scale
measurement of ChatGPT's reliability in the generic QA scenario with a
carefully curated set of 5,695 questions across ten datasets and eight domains.
We find that ChatGPT's reliability varies across different domains, especially
underperforming in law and science questions. We also demonstrate that system
roles, originally designed by OpenAI to allow users to steer ChatGPT's
behavior, can impact ChatGPT's reliability. We further show that ChatGPT is
vulnerable to adversarial examples, and even a single character change can
negatively affect its reliability in certain cases. We believe that our study
provides valuable insights into ChatGPT's reliability and underscores the need
for strengthening the reliability and security of large language models (LLMs)
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