Umbral calculus

Known as: Umbral Operator, Umbral, Umbral algebra

In mathematics before the 1970s, the term umbral calculus referred to the surprising similarity between seemingly unrelated polynomial equations and…

Papers overview

Semantic Scholar uses AI to extract papers important to this topic.

2013

We present simultaneous photospheric and chromospheric observations of the trailing sunspot in NOAA 10904, obtained with the…

2012

We employ high-resolution filtergrams and polarimetric measurements from Hinode to follow the evolution of a sunspot for eight…

2011

The first X-class flare of the current solar cycle 24 occurred in Active Region NOAA 11158 during its central meridian passage on…

2010

Efforts to model sunspots based on helioseismic signatures need to discriminate between the effects of (1) a strong magnetic…

2009

In this paper we use the viewpoint of the formal calculus underlying vertex operator algebra theory to study certain aspects of…

2008

High-resolution imaging observations from the Hinode spacecraft in the Ca ii H line are employed to study the dynamics of the…

Highly Cited

2006

Highly Cited

2006

We have observed high-resolution intensity spectra near the Fe I 1564.8 nm line at a single umbral point corresponding to the…

1997

1993

1992