553 research outputs found
A review and road map of entrepreneurial equity financing research
Equity financing in entrepreneurship primarily includes venture capital, corporate venture capital, angel investment, crowdfunding, and accelerators. We take stock of venture financing research to date with two main objectives: (a) to integrate, organize, and assess the large and disparate literature on venture financing; and (b) to identify key considerations relevant for the domain of venture financing moving forward. The net effect is that organizing and assessing existing research in venture financing will assist in launching meaningful, theory-driven research as existing funding models evolve and emerging funding models forge new frontiers
Radiation from a moving Scalar Source
We study classical radiation and quantum bremsstrahlung effect of a moving
point scalar source. Our classical analysis provides another example of
resolving a well-known apparent paradox, that of whether a constantly
accelerating source radiates or not. Quantum mechanically, we show that for a
scalar source with arbitrary motion, the tree level emission rate of scalar
particles in the inertial frame equals the sum of emission and absorption rates
of zero-energy Rindler particles in the Rindler frame. We then explicitly
verify this result for a source undergoing constant proper acceleration.Comment: 15 pages, CU-TP-59
Dynamics of Quantum Phase Transition in an Array of Josephson Junctions
We study the dynamics of the Mott insulator-superfluid quantum phase
transition in a periodic 1D array of Josephson junctions. We show that crossing
the critical point diabatically i.e. at a finite rate with a quench time
induces finite quantum fluctuations of the current around the loop
proportional to . This scaling could be experimentally verified
with in array of weakly coupled Bose-Einstein condensates or superconducting
grains.Comment: 4 pages in RevTex, 3 .eps figures; 2 references added; accepted for
publication in Phys.Rev.Let
Fluctuation-dissipation theorem and the Unruh effect of scalar and Dirac fields
We present a simple and systematic method to calculate the Rindler noise,
which is relevant to the analysis of the Unruh effect, by using the
fluctuation-dissipative theorem. To do this, we calculate the dissipative
coefficient explicitly from the equations of motion of the detector and the
field. This method gives not only the correct answer but also a hint as to the
origin of the apparent statistics inversion effect. Moreover, this method is
generalized to the Dirac field, by using the fermionic fluctuation-dissipation
theorem. We can thus confirm that the fermionic fluctuation-dissipation theorem
is working properly.Comment: 26 page
Decoherence, Chaos, and the Correspondence Principle
We present evidence that decoherence can produce a smooth
quantum-to-classical transition in nonlinear dynamical systems. High-resolution
tracking of quantum and classical evolutions reveals differences in expectation
values of corresponding observables. Solutions of master equations demonstrate
that decoherence destroys quantum interference in Wigner distributions and
washes out fine structure in classical distributions bringing the two closer
together. Correspondence between quantum and classical expectation values is
also re-established.Comment: 4 pages, 2 figures (color figures embedded at low resolution), uses
RevTeX plus macro (included). Phys. Rev. Lett. (in press
The Josephson plasmon as a Bogoliubov quasiparticle
We study the Josephson effect in alkali atomic gases within the two-mode
approximation and show that there is a correspondence between the Bogoliubov
description and the harmonic limit of the phase representation. We demonstrate
that the quanta of the Josephson plasmon can be identified with the Bogoliubov
excitations of the two-site Bose fluid. We thus establish a mapping between the
Bogoliubov approximation for the many-body theory and the linearized pendulum
Hamiltonian.Comment: 9 pages, LaTeX, submitted to J. Phys.
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