26,064 research outputs found
A comment on "Ab initio calculations of pressure-dependence of high-order elastic constants using finite deformations approach" by I. Mosyagin, A.V. Lugovskoy, O.M. Krasilnikov, Yu.Kh. Vekilov, S.I. Simak and I.A. Abrikosov
Recently, I. Mosyagin, A.V. Lugovskoy, O.M. Krasilnikov, Yu.Kh. Vekilov, S.I.
Simak and I.A. Abrikosov in the paper: "Ab initio calculations of
pressure-dependence of high-order elastic constants using finite deformations
approach"[Computer Physics Communications 220 (2017) 2030] presented a
description of a technique for ab initio calculations of the pressure
dependence of second- and third-order elastic constants. Unfortunately, the
work contains serious and fundamental flaws in the field of finite-deformation
solid mechanics.Comment: 3 pages, 0 figure
Quantum fluctuations of spacetime generate quantum entanglement between gravitationally polarizable subsystems
There should be quantum vacuum fluctuations of spacetime itself, if we accept
that the basic quantum principles we are already familiar with apply as well to
a quantum theory of gravity. In this paper, we study, in linearized quantum
gravity, the quantum entanglement generation at the neighborhood of the initial
time between two independent gravitationally polarizable two-level subsystems
caused by fluctuating quantum vacuum gravitational fields in the framework of
open quantum systems. A bath of fluctuating quantum vacuum gravitational fields
serves as an environment that provides indirect interactions between the two
gravitationally polarizable subsystems, which may lead to entanglement
generation. We find that the entanglement generation is crucially dependent on
the polarizations, i.e, they cannot get entangled in certain circumstances when
the polarizations of the subsystems are different while they always can when
the polarizations are the same. We also show that the presence of a boundary
may render parallel aligned subsystems entangled which are otherwise
unentangled in a free space. However, the presence of the boundary does not
help in terms of entanglement generation if the two subsystems are vertically
aligned.Comment: 18 pages, 4 figure
The Effect of Product Recommendations on Online Investor Behaviors
Despite the popularity of product recommendations on online investment
platforms, few studies have explored their impact on investor behaviors. Using
data from a global e-commerce platform, we apply regression discontinuity
design to causally examine the effects of product recommendations on online
investors' mutual fund investments. Our findings indicate that recommended
funds experience a significant rise in purchases, especially among low
socioeconomic status investors who are most influenced by these
recommendations. However, investors tend to suffer significantly worse
investment returns after purchasing recommended funds, and this negative impact
is also most significant for investors with low socioeconomic status. To
explain this disparity, we find investors tend to gather less information and
expend reduced effort in fund research when buying recommended funds.
Furthermore, investors' redemption timing of recommended funds is less optimal
than non-recommended funds. We also find that recommended funds experience a
larger return reversal than non-recommended funds. In conclusion, product
recommendations make investors behave more irrationally and these negative
consequences are most significant for investors with low socioeconomic status,
which can amplify wealth inequality among investors in financial markets
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