16,945 research outputs found
Cohomologies of locally conformally symplectic manifolds and solvmanifolds
We study the Morse-Novikov cohomology and its almost-symplectic counterpart
on manifolds admitting locally conformally symplectic structures. More
precisely, we introduce lcs cohomologies and we study elliptic Hodge theory,
dualities, Hard Lefschetz Condition. We consider solvmanifolds and
Oeljeklaus-Toma manifolds. In particular, we prove that Oeljeklaus-Toma
manifolds with precisely one complex place, and under an additional arithmetic
condition, satisfy the Mostow property. This holds in particular for the Inoue
surface of type
Classification of simple linearly compact Kantor triple systems over the complex numbers
Simple finite dimensional Kantor triple systems over the complex numbers are
classified in terms of Satake diagrams. We prove that every simple and linearly
compact Kantor triple system has finite dimension and give an explicit
presentation of all the classical and exceptional systems.Comment: 46 pages, 3 tables; v2: Major revision of the introduction; v3: Final
version to appear in Journal of Algebr
Symplectic cohomologies and deformations
In this note we study the behavior of symplectic cohomology groups under
symplectic deformations. Moreover, we show that for compact almost-K\"ahler
manifolds with -pure and full the
space of de Rham harmonic forms is contained in the space of
symplectic-Bott-Chern harmonic forms. Furthermore, we prove that the second
non-HLC degree measures the gap between the de Rham and the
symplectic-Bott-Chern harmonic forms
Some remarks on Hermitian manifolds satisfying K\"ahler-like conditions
We study Hermitian metrics whose Bismut connection satisfies the
first Bianchi identity in relation to the SKT condition and the parallelism of
the torsion of the Bimut connection. We obtain a characterization of complex
surfaces admitting Hermitian metrics whose Bismut connection satisfy the first
Bianchi identity and the condition , for every
tangent vectors , in terms of Vaisman metrics. These conditions, also
called Bismut K\"ahler-like, have been recently studied in [D. Angella, A.
Otal, L. Ugarte, R. Villacampa, On Gauduchon connections with K\"ahler-like
curvature, to appear in Commun. Anal. Geom., arXiv:1809.02632 [math.DG]], [Q.
Zhao, F. Zheng, Strominger connection and pluriclosed metrics, arXiv:1904.06604
[math.DG]], [S. T. Yau, Q. Zhao, F. Zheng, On Strominger K\"ahler-like
manifolds with degenerate torsion, arXiv:1908.05322 [math.DG]]. Using the
characterization of SKT almost abelian Lie groups in [R. M. Arroyo, R.
Lafuente, The long-time behavior of the homogeneous pluriclosed flow, Proc.
London Math. Soc. (3), 119, (2019), 266-289], we construct new examples of
Hermitian manifolds satisfying the Bismut K\"ahler-like condition. Moreover, we
prove some results in relation to the pluriclosed flow on complex surfaces and
on almost abelian Lie groups. In particular, we show that, if the initial
metric has constant scalar curvature, then the pluriclosed flow preserves the
Vaisman condition on complex surfaces.Comment: Theorem B and Lemma 5.1 modified. Added Remark 5.
Under What Conditions Can Inflation Targeting Be Adopted? The Experience of Emerging Markets
While there have been numerous studies of inflation targeting in industrial countries, there has been much less analysis of the effects of inflation targeting in emerging market countries. Based on a new and detailed survey of 31 central banks, this paper shows that inflation targeting in emerging-market countries brings significant benefits to the countries that adopt it relative to other strategies, such as money or exchange rate targeting. Indeed, by comparing the performance of the inflation-targeting countries with a sample of countries that pursue other regimes we show that there are significant improvements in anchoring both inflation and inflation expectations with no adverse effects on output. In addition, under inflation targeting interest rates, exchange rates, and international reserves are less volatile, and the risk of currency crises relative to money or exchange rate targets is smaller. Interestingly, IT seems to outperform exchange rate pegs—even when only successful pegs are chosen in comparison. The survey evidence indicates that it is unnecessary for countries to meet a stringent set of institutional, technical, and economic “preconditions” for the successful adoption of inflation targeting.
Strong pressure-energy correlations in liquids as a configuration space property: Simulations of temperature down jumps and crystallization
Computer simulations recently revealed that several liquids exhibit strong
correlations between virial and potential energy equilibrium fluctuations in
the NVT ensemble [U. R. Pedersen {\it et al.}, Phys. Rev. Lett. {\bf 100},
015701 (2008)]. In order to investigate whether these correlations are present
also far from equilibrium constant-volume aging following a temperature down
jump from equilibrium was simulated for two strongly correlating liquids, an
asymmetric dumbbell model and Lewis-Wahnstr{\"o}m OTP, as well as for SPC water
that is not strongly correlating. For the two strongly correlating liquids
virial and potential energy follow each other closely during the aging towards
equilibrium. For SPC water, on the other hand, virial and potential energy vary
with little correlation as the system ages towards equilibrium. Further proof
that strong pressure-energy correlations express a configuration space property
comes from monitoring pressure and energy during the crystallization (reported
here for the first time) of supercooled Lewis-Wahnstr{\"o}m OTP at constant
temperature
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