10,479 research outputs found
Quantum Reciprocity Conjecture for the Non-Equilibrium Steady State
By considering the lack of history dependence in the non-equilibrium steady
state of a quantum system we are led to conjecture that in such a system, there
is a set of quantum mechanical observables whose retarded response functions
are insensitive to the arrow of time, and which consequently satisfy a quantum
analog of the Onsager reciprocity relations. Systems which satisfy this
conjecture can be described by an effective Free energy functional. We
demonstrate that the conjecture holds in a resonant level model of a multi-lead
quantum dot.Comment: References revised to take account of related work on Onsager
reciprocity in mesoscopics by Christen, and in hydrodynamics by Mclennan,
Dufty and Rub
Black hole formation from colliding bubbles
Some indication of conditions that are necessary for the formation of black
holes from the collision of bubbles during a supercooled phase transition in
the the early universe are explored. Two colliding bubbles can never form a
black hole. Three colliding bubbles can refocus the energy in their walls to
the extent that it becomes infinite.Comment: 12 pages, NCL93-TP13 (RevTeX
Probabilistic Approach to Time-Dependent Load-Transfer Models of Fracture
A probabilistic method for solving time-dependent load-transfer models of
fracture is developed. It is applicable to any rule of load redistribution,
i.e, local, hierarchical, etc. In the new method, the fluctuations are
generated during the breaking process (annealed randomness) while in the usual
method, the random lifetimes are fixed at the beginning (quenched disorder).
Both approaches are equivalent.Comment: 13 pages, 4 figures. To appear in Phys.Rev.
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Controls on development and diversity of Early Archean stromatolites
The ≈3,450-million-year-old Strelley Pool Formation in Western Australia contains a reef-like assembly of laminated sedimentary accretion structures (stromatolites) that have macroscale characteristics suggestive of biological influence. However, direct microscale evidence of biology—namely, organic microbial remains or biosedimentary fabrics—has to date eluded discovery in the extensively-recrystallized rocks. Recently-identified outcrops with relatively good textural preservation record microscale evidence of primary sedimentary processes, including some that indicate probable microbial mat formation. Furthermore, we find relict fabrics and organic layers that covary with stromatolite morphology, linking morphologic diversity to changes in sedimentation, seafloor mineral precipitation, and inferred microbial mat development. Thus, the most direct and compelling signatures of life in the Strelley Pool Formation are those observed at the microscopic scale. By examining spatiotemporal changes in microscale characteristics it is possible not only to recognize the presence of probable microbial mats during stromatolite development, but also to infer aspects of the biological inputs to stromatolite morphogenesis. The persistence of an inferred biological signal through changing environmental circumstances and stromatolite types indicates that benthic microbial populations adapted to shifting environmental conditions in early oceans
Magnetic Wormholes and Vertex Operators
We consider wormhole solutions in Euclidean dimensions. A duality
transformation is introduced to derive a new action from magnetic wormhole
action of Gupta, Hughes, Preskill and Wise. The classical solution is
presented. The vertex operators corresponding to the wormhole are derived.
Conformally coupled scalars and spinors are considered in the wormhole
background and the vertex operators are computed. ( To be published in Phys.
Rev. D15)Comment: 18 pages of RevTex, preprint IP/BBSR/94-2
Wormholes and Supersymmetry
Revisions: reference added to: G. Gilbert, {\sl Nucl.Phys.} {\bf B328}, 159
(1989)Comment: 29 pages, jnl, McGill/92-2
Interacting Electrons on a Square Fermi Surface
Electronic states near a square Fermi surface are mapped onto quantum chains.
Using boson-fermion duality on the chains, the bosonic part of the interaction
is isolated and diagonalized. These interactions destroy Fermi liquid behavior.
Non-boson interactions are also generated by this mapping, and give rise to a
new perturbation theory about the boson problem. A case with strong repulsions
between parallel faces is studied and solved. There is spin-charge separation
and the square Fermi surface remains square under doping. At half-filling,
there is a charge gap and insulating behavior together with gapless spin
excitations. This mapping appears to be a general tool for understanding the
properties of interacting electrons on a square Fermi surface.Comment: 25 pages, Nordita preprint 94/22
Gravitation Interaction and Electromagnetic Interaction in the Relativistic Universe with Total Zero and Local Non-Zero Energy
In the model of flat expansive homogeneous and isotropic relativistic
universe with total zero and local non-zero energy the gravitation energy of
bodies and the elecromagnetic energy of charged bodies can be localised.Comment: LaTeX, 10 pages, 1 figur
Co-operative Kondo Effect in the two-channel Kondo Lattice
We discuss the possibility of a co-operative Kondo effect driven by channel
interference in a Kondo lattice where local moments are coupled to a single
Fermi sea via two orthogonal scattering channels. In this situation, the
channel quantum number is not conserved. We argue that the absence of channel
conservation causes the Kondo effect in the two channels to constructively
interfere, giving rise to a superconducting condensate of composite pairs,
formed between the local moments and the conduction electrons. Our arguments
are based on the observation that a heavy Fermi surface gives rise to zero
modes for Kondo singlets to fluctuate between screening channels of different
symmetry, producing a divergent composite pair susceptibility. Secondary
screening channels couple to these divergent fluctuations, promoting an
instability into a state with long-range composite order. We present detailed a
detailed mean-field theory for this superconducting phase, and discuss the
possible implications for heavy fermion physics.Comment: 23 double column pages. 9 fig
Bose-Einstein-condensed gases with arbitrary strong interactions
Bose-condensed gases are considered with an effective interaction strength
varying in the whole range of the values between zero and infinity. The
consideration is based on the usage of a representative statistical ensemble
for Bose systems with broken global gauge symmetry. Practical calculations are
illustrated for a uniform Bose gas at zero temperature, employing a
self-consistent mean-field theory, which is both conserving and gapless.Comment: Latex file, 23 pages, 4 figure
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