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## Main Question or Discussion Point

perhaps is a dumb quetion but,

given a IR divergent integral (diverges whenever x tends to 0)

[tex] \int_{0}^{\infty} \frac{dx}{x^{3}} [/tex]

then using a simple change of variables x=1/u the IR integral becomes an UV divergent integral

[tex] \int_{0}^{\infty} udu [/tex] which is an UV divergent integral (it diverges whenever x tends to infinity)

then why we call IR or UV divergences if they are essentially the same thing ??

given a IR divergent integral (diverges whenever x tends to 0)

[tex] \int_{0}^{\infty} \frac{dx}{x^{3}} [/tex]

then using a simple change of variables x=1/u the IR integral becomes an UV divergent integral

[tex] \int_{0}^{\infty} udu [/tex] which is an UV divergent integral (it diverges whenever x tends to infinity)

then why we call IR or UV divergences if they are essentially the same thing ??