Wilhelm Hartwig †

Hartwig symbols

Response to Hartwig and Davies

and indeed many of the other analyses reported in our paper do not suffer from potential bias due to weak instruments. Hartwig and Davies did, however, suggest that we could have used estimates from an external source to obtain less biased results in our MR-Egger analyses. Whereas we agree that this would be good practice in most situations, we do not feel that it would have been appropriate in...

Vita: Friedrich Wilhelm Wiener

We report on the life and work of F. Wiener, whom we confused with N. Wiener in a previous article.

Carl Wilhelm Scheele

Figure 3. "Scheele Haus," the birthplace (1742) of Scheele, is the center building, located at Fiihrstrafie 23, Stra/sund, Gennany (N 54° 18.99; E 13° 05.56). This building is elegantly marked with a plaque and a small exhibit inside. The view is eastward, downhill toward the Baltic Sea only 200 meters away and from which cold winds often blow up the street. Occasional plaques in the city datin...

The Fisher-Hartwig Conjecture and Toeplitz Eigenvalues

The conjecture of Fisher and Hartwig, published in 1968, describes the asymptotic expansion of Toeplitz determinants with singular generating functions. For more than twenty years progress was made in extending the validity of the conjecture, but recent computer experiments led to counter-examples that show the limits of the original conjecture and pointed the way to a revised conjecture. This ...