2,746 research outputs found
U.S. Stock Market Crashes and Their Aftermath: Implications for Monetary Policy
This paper examines fifteen historical episodes of stock market crashes and their aftermath in the United States over the last one hundred years. Our basic conclusion from studying these episodes is that financial instability is the key problem facing monetary policy makers and not stock market crashes, even if they reflect the possible bursting of a bubble. With a focus on financial stability rather than the stock market, the response of central banks to stock market fluctuations is more likely to be optimal and maintain support for the independence of the central bank.
Brans-Dicke geometry
We reveal the non-metric geometry underlying omega-->0 Brans-Dicke theory by
unifying the metric and scalar field into a single geometric structure. Taking
this structure seriously as the geometry to which matter universally couples,
we show that the theory is fully consistent with solar system tests. This is in
striking constrast with the standard metric coupling, which grossly violates
post-Newtonian experimental constraints.Comment: 8 pages, v2 with additional comment and reference
How Do Legal Differences and Learning Affect Financial Contracts?
We analyze venture capital (VC) investments in twenty-three non-U.S. countries and compare them to U.S. VC investments. We describe how the contracts allocate cash flow, board, liquidation, and other control rights. In univariate analyses, contracts differ across legal regimes. However, more experienced VCs implement U.S.-style contracts regardless of legal regime. In most specifications, legal regime becomes insignificant controlling for VC sophistication. VCs who use U.S.-style contracts fail significantly less often. The results suggest that U.S.-style contracts are efficient across a wide range of legal regimes. The evolution of contracts is consistent with financial contracting theories and costly learning.Venture capital; Financial contracting; Law and finance; Corporate governance
Weak antiferromagnetism and dimer order in quantum systems of coupled tetrahedra
We analyze the phases of an S=1/2 spin model on a lattice of coupled
tetrahedra. The presence of both Heisenberg and antisymmetric,
Dzyaloshinsky-Moriya interactions can lead to two types of symmetry-broken
states: non-magnetic dimer order and, unexpectedly, exotic 4 sub-lattice weak
antiferromagnetic order - a state with a generically small ordered moment and
non-zero chirality. External magnetic field also induces weak
antiferromagnetism co-existing with strong dimer correlations in the ground
state.
These states are formed as a result of broken Ising symmetries and exhibit a
number of unusual properties.Comment: 5 pages, 4 figures; final version to appear in Phys. Rev.
Geometry for the accelerating universe
The Lorentzian spacetime metric is replaced by an area metric which naturally
emerges as a generalized geometry in quantum string and gauge theory. Employing
the area metric curvature scalar, the gravitational Einstein-Hilbert action is
re-interpreted as dynamics for an area metric. Without the need for dark energy
or fine-tuning, area metric cosmology explains the observed small acceleration
of the late Universe.Comment: 4 pages, 1 figur
Cosmological constraints on a classical limit of quantum gravity
We investigate the cosmology of a recently proposed deformation of Einstein
gravity, emerging from quantum gravity heuristics. The theory is constructed to
have de Sitter space as a vacuum solution, and thus to be relevant to the
accelerating universe. However, this solution turns out to be unstable, and the
true phase space of cosmological solutions is significantly more complex,
displaying two late-time power-law attractors -- one accelerating and the other
dramatically decelerating. It is also shown that non-accelerating cosmologies
sit on a separatrix between the two basins of attraction of these attractors.
Hence it is impossible to pass from a decelerating cosmology to an accelerating
one, as required in standard cosmology for consistency with nucleosynthesis and
structure formation and compatibility with the data inferred from supernovae
Ia. We point out that alternative models of the early universe, such as the one
investigated here might provide possible ways to circumvent these requirements.Comment: 14 pages, 2 figures, REVTeX
Tools to integrate organoleptic quality criteria into breeding programs
This technical booklet provides methodologies and guidance to implement sensory evaluations for organoleptic quality assessment in multi-actor-projects for organic agriculture. It presents five detailed tests that can be used in sensory evaluation, methodologies on how to prepare the samples and a glossary. This booklet has been developed under Solibam project and updated during Diversifood project
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