Something moving faster than light should have imaginary mass, like photons have zero mass and thus travel at $c$.

I have read the article of physicist E. C. George Sudarshan.herehttp://quest.ph.utexas.edu/sudarshan_tachyons.html He said taking mass to be imaginary we get real energy and momentum. (I think I have understood that.) However, if something moves at a speed greater than $c$, its proper time $\tau=t\sqrt{1-v^2/c^2}$ becomes imaginary (where $t$ is coordinate time).

Does this imply causality violation? Does imaginary time mean time is going backward?

Something moving faster than light should have imaginary mass, like photons have zero mass and thus travel at $c$.

I have read this article of physicist E. C. George Sudarshan.

He said taking mass to be imaginary we get real energy and momentum. (I think I have understood that.) However, if something moves at a speed greater than $c$, its proper time $\tau=t\sqrt{1-v^2/c^2}$ becomes imaginary (where $t$ is coordinate time).

Does this imply causality violation? Does imaginary time mean time is going backward?

Something moving faster than light should have imaginary mass, like photons have zero mass and thus travel at $c$.

I have read the article of physicist E. C. George Sudarshan. He said taking mass to be imaginary we get real energy and momentum. (I think I have understood that.) However, if something moves at a speed greater than $c$, its proper time $\tau=t\sqrt{1-v^2/c^2}$ becomes imaginary (where $t$ is coordinate time).

Does this imply causality violation? Does imaginary time mean time is going backward?

Something moving faster than light should have imaginary mass, like photons have zero mass and thus travel at $c$.

I have read the article of physicist E. C. George Sudarshan.herehttp://quest.ph.utexas.edu/sudarshan_tachyons.html He said taking mass to be imaginary we get real energy and momentum. (I think I have understood that.) However, if something moves at a speed greater than $c$, its proper time $\tau=t\sqrt{1-v^2/c^2}$ becomes imaginary (where $t$ is coordinate time).

Does this imply causality violation? Does imaginary time mean time is going backward?

Something moving faster than light should have imaginary mass, like photons have zero mass and thus travel at 'c'. I have read the article of physicist E. C. George Sudarshan. He said taking mass to be imaginary we get real energy and momentum. (I think I have understood that). But if something moves at a speed greater than 'c', its proper time become imaginary, considering propertime=coordinate time*(1-v^2/c^2)^1/2. But does this imply causality violation? Does imaginary time mean time is going backward?

Something moving faster than light should have imaginary mass, like photons have zero mass and thus travel at $c$.

I have read the article of physicist E. C. George Sudarshan. He said taking mass to be imaginary we get real energy and momentum. (I think I have understood that.) However, if something moves at a speed greater than $c$, its proper time $\tau=t\sqrt{1-v^2/c^2}$ becomes imaginary  (where $t$ is coordinate time).

Does this imply causality violation? Does imaginary time mean time is going backward?