In questo lavoro si costruisce, mediante interpolazione, una norma naturale per operatori lineari continui coercivi e non simmetrici. Più precisamente, si cerca una norma con stesse le proprietà che ha la norma dell'energia quando si considerano operatori simmetrici: si dimostrano cioè, rispetto a tale norma, stime di continuità e di inf-sup indipendenti dall'operatore. In particolare, si prende in considerazione l'operatore di diffusione-trasporto-reazione lineare: si ottengono quindi stime di continuità e inf-sup indipendenti dai coefficienti dell'operatore, pertanto significative anche nel regime di trasporto dominante. I risultati qui presentati possono servire ad una più approfindita comprensione e analisi di tecniche numeriche per problemi non simmetrici.
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