6,026 research outputs found
Solidity of viscous liquids. III. Alpha relaxation
It is suggested that the high-frequency decay of the alpha
loss in highly viscous liquids, which appears to be generic, is a manifestation
of a negative long-time tail as typically encountered in stochastic dynamics.
The proposed mechanism requires that the coherent diffusion constant is much
larger than estimated from the alpha relaxation time. This is justified by
reference to the solidity of viscous liquids in an argument which, by utilizing
the irrelevance of momentum conservation at high viscosity and introducing a
center of mass diffusion constant, implies that at high viscosity the coherent
diffusion constant is much larger than the incoherent diffusion constant
All-Order Corrections To Higgs Boson Production In Association With Jets
We present a new framework for calculating multi-jet observables. The
framework is based on the factorisation of scattering amplitudes in the
kinematical limit of large invariant mass between all particles. We show that
by constraining the analyticity of scattering amplitudes away from this limits,
we get good agreement order by order with the full, fixed order perturbative
calculation at the low orders where these are available, and therefore get firm
predictions on the all-order behaviour. As an example, we study Higgs boson
production through gluon fusion in association with at least two jets at the
LHC.Comment: Invited talk at 44th Rencontres de Moriond on QCD and High Energy
Interactions, La Thuile, Valle d'Aosta, Italy, 14-21 Mar 200
Elastic Models for the Non-Arrhenius Relaxation Time of Glass-Forming Liquids
We first review the phenomenology of viscous liquids and the standard models
used for explaining the non-Arrhenius average relaxation time. Then the focus
is turned to the so-called elastic models, arguing that these models are all
equivalent in the Einstein approximation (where the short-time elastic
properties are all determined by just one effective, temperature-dependent
force constant). We finally discuss the connection between the elastic models
and two well-established research fields of condensed-matter physics: point
defects in crystals and solid-state diffusion.Comment: Paper presented at the IWCS2005 (Nov. 2005, Sendai, Japan
Solidity of viscous liquids II: Anisotropic flow events
Recent findings on the displacements in the surroundings of isotropic flow
events in viscous liquids [Phys. Rev. E, to appear Feb. 1999] are generalized
to the anisotropic case. Also, it is shown that a flow event is characterized
by a dimensionless number reflecting the degree of anisotropy.Comment: Rev-tex file, no figures, submitted to Phys. Rev. E as a Brief Repor
On the possible existence of crystallites in glass-forming liquids
We speculate that glass-forming liquids may contain fairly large and
well-defined crystallites. This is based on arguing that the slowly relaxing
"frozen-in" stresses characterizing ultraviscous liquids increase the barrier
for nucleation, thus allowing for larger unstable crystallites than otherwise
possible. The frozen-in stresses also deform the crystallites, making their
observation difficult; specifically it is argued that a situation where 1/N of
the molecules form N X N X N crystallites would be hard to detect by standard
X-ray or neutron scattering experiments
Robin Hood Justice: Why Robin Hood Took from the Rich and Gave to the Poor (and We Should Too)
The legend of Robin Hood exemplifies a distinct concern of justice neglected by theorists: the distributive results of systemic injustices. Robin Hood’s redistributive activities are justified by the principle that the distributive results of systemic injustices are unjust and should be corrected. This principle has relevance beyond the legend: since current inequalities in the US are results of systemic injustices, the US has good reason to take from the rich and give to the poor
NVU perspective on simple liquids' quasiuniversality
The last half century of research into the structure, dynamics, and
thermodynamics of simple liquids has revealed a number of approximate
universalities. This paper argues that simple liquids' reduced-coordinate
constant-potential-energy hypersurfaces constitute a quasiuniversal family of
compact Riemannian manifolds parameterized by a single number, from which
follows these liquids' quasiuniversalities
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