# Is ARMA(0,0) equivalent to white noise?

If the EACF of my TS suggests ARMA(0,0) and the Box-Ljung test does not suggest my TS has correlation, can I conclude that my TS is white noise or merely that there is no reason to suspect that it is not white noise?

Conversely, if my TS is white noise, will I necessarily get ARMA(0,0) from EACF, ACF, PACF, etc?

If you truly knew that your data generating process (DGP) is ARMA(0,0): $x_t=c+\varepsilon_t$, then, yes, it is, basically, a white noise.