1,859 research outputs found
A Game-theoretic Approach for Provably-Uniform Random Number Generation in Decentralized Networks
Many protocols in distributed computing rely on a source of randomness,
usually called a random beacon, both for their applicability and security. This
is especially true for proof-of-stake blockchain protocols in which the next
miner or set of miners have to be chosen randomly and each party's likelihood
to be selected is in proportion to their stake in the cryptocurrency.
Current random beacons used in proof-of-stake protocols, such as Ouroboros
and Algorand, have two fundamental limitations: Either (i)~they rely on
pseudorandomness, e.g.~assuming that the output of a hash function is uniform,
which is a widely-used but unproven assumption, or (ii)~they generate their
randomness using a distributed protocol in which several participants are
required to submit random numbers which are then used in the generation of a
final random result. However, in this case, there is no guarantee that the
numbers provided by the parties are uniformly random and there is no incentive
for the parties to honestly generate uniform randomness. Most random beacons
have both limitations.
In this thesis, we provide a protocol for distributed generation of
randomness. Our protocol does not rely on pseudorandomness at all. Similar to
some of the previous approaches, it uses random inputs by different
participants to generate a final random result. However, the crucial difference
is that we provide a game-theoretic guarantee showing that it is in everyone's
best interest to submit uniform random numbers. Hence, our approach is the
first to incentivize honest behavior instead of just assuming it. Moreover, the
approach is trustless and generates unbiased random numbers. It is also
tamper-proof and no party can change the output or affect its distribution.
Finally, it is designed with modularity in mind and can be easily plugged into
existing distributed protocols such as proof-of-stake blockchains.Comment: 36 pages excluding reference. Game-theoretic Randomness for
Proof-of-Stake in MARBLE (2023
The standard cohomology of regular Courant algebroids
For any regular Courant algebroid over a smooth manifold with
characteristic distribution and ample Lie algebroid , we prove that
there exists a canonical homological vector field on the graded manifold
such that the associated dg manifold
, which we call the minimal model of the Courant algebroid ,
encodes all cohomological data of . Thereby, the standard cohomology
of can be identified with the cohomology
of the function space on . To compute
it, we find a natural transgression map [d_T] \colon
H^{\bullet}_{\operatorname{CE}}\big(A_E; S^{\diamond}(TM/F[-2])\big) \to
H^{\bullet+3}_{\CE}\big(A_E; S^{\diamond-1}(TM/F[-2])\big) from which we
construct a spectral sequence which converges to
. Moreover, we give applications to
generalized exact Courant algebroids and those arising from regular Lie
algebroids .Comment: 41 pages; the main body is rewritten; typos remove
Geographic structure of Chinese dialects: a computational dialectometric approach
Dialect classification is a long-standing issue in Chinese dialectology. Although various theories of Chinese dialect regions have been proposed, most have been limited by similar methodological issues, especially due to their reliance on the subjective analysis of dialect maps both individually and in the aggregate, as well as their focus on phonology over syntax and vocabulary. Consequently, we know relatively little about the geolinguistic underpinnings of Chinese dialect variation. Following a review of previous research in this area, this article presents a theory of Chinese dialect regions based on the first large-scale quantitative analysis of the data from the Linguistic Atlas of Chinese Dialects, which was collected between 2000 and 2008, providing the most up-to-date picture of the full Chinese dialect landscape. We identify and map a hierarchy of 10 major Chinese dialect regions, challenging traditional accounts. In addition, we propose a new theory of Chinese dialect formation to account for our findings
Scheme for sharing classical information via tripartite entangled states
We investigate schemes for quantum secret sharing and quantum dense coding
via tripartite entangled states. We present a scheme for sharing classical
information via entanglement swapping using two tripartite entangled GHZ
states. In order to throw light upon the security affairs of the quantum dense
coding protocol, we also suggest a secure quantum dense coding scheme via W
state in analogy with the theory of sharing information among involved users.Comment: 4 pages, no figure. A complete rewrritten vession, accepted for
publication in Chinese Physic
Effect of Samarium doping on the nucleation of fcc-Aluminum in undercooled liquids
The effect of Sm doping on the fcc-Al nucleation was investigated in Al-Sm
liquids with low Sm concentrations (xSm) with molecular dynamics simulations.
The nucleation in the moderately undercooled liquid is achieved by the recently
developed persistent-embryo method. Systematically computing the nucleation
rate with different xSm (xSm=0%, 1%, 2%, 3%, 5%) at 700 K, we found Sm dopant
reduces the nucleation rate by up to 25 orders of magnitudes with only 5%
doping concentration. This effect is mostly associated with the increase in the
free energy barrier with a minor contribution from suppression of the
attachment to the nucleus caused by Sm doping.Comment: 4 figure
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