Spectra that are Newton after extension or translation
Linear Algebra and Its Applications
The appending of real numbers, and also conjugate pairs, to Newton spectra is studied to understand circumstances in which the Newton inequalities are preserved. Appending to a non-Newton spectrum to achieve the Newton inequalities is also studied. Finally the translations of Newton spectra that are Newton are also studied. A sample result is that any number of positive real numbers may be appended to a Newton spectrum, to retain the Newton property, when the Newton coefficients are positive, while any Newton spectrum may be made non-Newton by appending a conjugate pair with positive real part and sufficiently large imaginary part. (C) 2010 Elsevier Inc. All rights reserved.
Pisonero, M.; Johnson, C. R.; and Marijuan, C., Spectra that are Newton after extension or translation (2010). Linear Algebra and Its Applications, 433(10-Aug), 1623-1641.