# Search results

1. ### Klein bottle

Can anyone explain in laymans terms what a Kleins bottle is . I have encountered the definition that it is a non orientable surface , that it is a 2 dimensional manifold in 4 dimensions. I dont have a clue what a non orientable surface is , or what a manifold is . I also dont have any idea...
2. ### What is Riemann zeta function.

Could anyone tell me what is the Riemann zeta function. On Wikipedia , the definition has been given for values with real part > 1 , as : Sum ( 1 / ( n^-s) ) as n varies from 1 to infinity. but what is the definition for other values of s ? It is mentioned that the zeta function is the...
3. ### Books on tensor analysis

Hi All , I am looking for a book on introduction to tensor analysis . I do not have much of a background in mathematics .. I have an undergraduate degree in engineering . My aim is to understand General Relativity ... I would also like to understand Quantum Mechanics ... It feels odd that...
4. ### The expansion of the universe

The general theory of relativity leads to the conclusion that the fabric of space time is ever expanding . This has indeed been proved by Hubble when he found out that the galaxies are moving away from each other.In fact all stellar bodies are moving away from each other. My question is this ...
5. ### No of primes less than a given number

After reading 1 of the posts in this forum , I had a look at the millenium problems . There I saw the problem of proving if N=NP . I really did not understand what is NP and what is P ( I checked the Wikipedia link but this got me even more confused ... It talked of a non deterministic...
6. ### Perfect square in 2 bases

Does anyone know if its possible to check whether a number is a perfect square in 2 different bases ? ( I dont mean the representation of a number in 2 different bases - coz that would be a ridiculous question , what I mean is consider a no say xyz - is it possible to prove / disprove that it is...