Volatile Hiring: Uncertainty in Search and Matching Models

In search-and-matching models, the nonlinear nature of search frictions increases average unemployment rates during periods with higher volatility. These frictions are not, however, by themselves sufficient to raise unemployment following an increase in perceived uncertainty; though they may do so in conjunction with the common assumption of wages being determined by Nash bargaining. Importantly, option-value considerations play no role in the standard model with free entry. In contrast, when the mass of entrepreneurs is finite and there is heterogeneity in firm-specific productivity, a rise in perceived uncertainty robustly increases the option value of waiting and reduces job creation

Exact present solution with consistent future approximation: a gridless algorithm to solve stochastic dynamic models

This paper proposes an algorithm that finds model solutions at a particular point in the state space by solving a simple system of equations. The key step is to characterize future behavior with a Taylor series expansion of the current period’s behavior around the contemporaneous values for the state variables. Since current decisions are solved from the original model equations, the solution incorporates nonlinearities and uncertainty. The algorithm is used to solve the model considered in Coeurdacier, Rey, and Winant (2011), which is a challenging model because it has no steady state and uncertainty is necessary to keep the model well behaved. We show that our algorithm can generate accurate solutions even when the model series are quite volatile. The solutions generated by the risky-steady-state algorithm proposed in Coeurdacier, Rey, and Winant (2011), in contrast, is shown to be not accurat

A method for mechanical generation of radio frequency fields in nuclear magnetic resonance force microscopy

We present an innovative method for magnetic resonance force microscopy (MRFM) with ultra-low dissipation, by using the higher modes of the mechanical detector as radio frequency (rf) source. This method allows MRFM on samples without the need to be close to an rf source. Furthermore, since rf sources require currents that give dissipation, our method enables nuclear magnetic resonance experiments at ultra-low temperatures. Removing the need for an on-chip rf source is an important step towards a MRFM which can be widely used in condensed matter physics.Comment: 7 pages, 5 figures, to be submitted to Physical Review Applie

Probing the magnetic moment of FePt micromagnets prepared by Focused Ion Beam milling

We investigate the degradation of the magnetic moment of a 300 nm thick FePt film induced by Focused Ion Beam (FIB) milling. A $1~\mu \mathrm{m} \times 8~\mu \mathrm{m}$ rod is milled out of a film by a FIB process and is attached to a cantilever by electron beam induced deposition. Its magnetic moment is determined by frequency-shift cantilever magnetometry. We find that the magnetic moment of the rod is $\mu = 1.1 \pm 0.1 \times 10 ^{-12} \mathrm{Am}^2$, which implies that 70% of the magnetic moment is preserved during the FIB milling process. This result has important implications for atom trapping and magnetic resonance force microscopy (MRFM), that are addressed in this paper.Comment: 4 pages, 4 figure

Probing the magnetic moment of FePt micromagnets prepared by Focus Ion Beam milling

Quantum Matter and Optic

New diagnostic and treatment strategies in renal artery stenosis: a promising pursuit or disappointment foretold?

Clinical management of renal artery stenosis has seen a major shift, after randomised clinical trials have shown no group benefit of endovascular intervention relative to optimal medical control. However, the inclusion criteria of these trials have been criticised for focusing on a subset of patients with atherosclerotic renal artery stenosis where intervention was unlikely to be beneficial. Moreover, new imaging and computational techniques have become available, which have the potential to improve identification of patients that will respond to interventional treatment. This review addresses the challenges associated with clinical decision making in patients with renal artery stenosis. Opportunities for novel diagnostic techniques to improve patient selection are discussed, along with ongoing Dutch studies and network initiatives that investigate these strategies