Abstract
We give an elementary proof of a theorem of Brickman, which establishes the convexity of the image of the unit sphere of a space with dimension at least three under a vector mapping into R2 whose component functions are quadratic forms. We also discuss some consequences of this theorem regarding the range of that mapping. © Heldermann Verlag Quadratic forms, convexity.
| Original language | English |
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| Pages (from-to) | 139-143 |
| Journal | Journal of Convex Analysis |
| Volume | 12 |
| Issue number | 1 |
| Publication status | Published - 1 Jan 2005 |