Now, let us carefully examine the colossal mistakes committed by the two physicists in obtaining the preposterous result:
The most that can be said, within the context of Ramanujan summation (a highly abstract mathematical setting) is that c, the constant of the series employed by Ramanujan (his "center of gravity" of a series), will equal -1/12.
By using the same reasoning, on the sum Σ1 (1 to infinity), c will equal -1/2.
However, the Abel and Cesaro sums of Σ1 are both infinity.
You cannot operate with highly divergent infinite series using the rules of convergent series: the results will be spurious.
Certain divergent series, like asymptotic series, can added/substracted, but under very strict rules.
Also, when using analytic continuation, you are actually substracting infinity from infinity to get something finite: again, an abstract mathematical operation with no connection to the real world.
There is no such thing as bosonic string theory in multiple dimensions, or the derivation of Casimir effect assuming zeta regularization:
https://web.archive.org/web/20120128042636/http://www.scientificexploration.org/journal/jse_09_4_phillips.pdf