Does someone know if  you can get married with same surname in upadhyay bahun. e.x marriage of poudel boy with a poudel girl if they r not related.

In my openion as loong as you guys are not within a "13 dine daju vhai" you should be fine. if you believe in science and human evolution ancestory is same.  surname, jat bhat etc all are created by the people later to keep the descipline and culture intact. when there was no rule of law, people used to follow those principles to keep the communal harmony. if you look the ancestory each and every person are brother and sisters even the surname is different.

This is not relevant in the current days. However, they look for different 'gotra' i guess.. Marriage between same gotra is still forbidden in bahun/chettri community i guess.

yes the last poster is right.In bahun and chettri marriage between the persons having same last names is forbidden.

note to previous poster: the poster before you does not say that 'marriage between the persons having same LAST NAMES is forbidden'  ,  he says 'SAME GOTRA is forbidden'.

note to previous poster, most of the times last name will have same GOTRA (except Pokharels); and thats the reason bhauns and chetris forbid the marriage between the persons having same LAST NAMES

On the other side, is this kind of statement called corollary, postulate, lemma or else ?

Note to the previous poster ( I am just following the same pattern here)...it is wrong when u say that most of the times same last name will have same GOTRA. And many are right; marriage between same gotra are forbidden, not the last name. But Even with the same gotra, they are starting looking more closely into other stuffs. I have both examples in my own family (kaka ko ani cousion ko), and I am chettri.

Marriage with the same surname is fine as long as they have different gotras. Its highly unrecommended to marry sb with the same gotra. its not superstitious but scientific too.When ya marry ppl with some gotras, it is likely to have lot of similar kinds of genes so when ya have kids its likely for the recessive genes to express and result in some kind of genetic defects.Let me explain: you might have a gene for a certain defect but ya might just be a carrier so ya donn have the defect but after crossing with a person of nearly same genetic make up your offspring might get the recessive gene from ya and your wife which makes the defect dominant (expressed visibly). 

Forget about same last name you are not supposed marry if you have same gotra but difeerent last name in bahuns and chettris. If you want to follow the tradition then you should not marry the person with same last name. Only in newars getting married to same last name is ok if you are separated by 7 generations at least.

एकै जात संग बिहे गर्दा T 21 बच्चा हुने प्रबल सम्भावना हुन्छ . तेसैले सके सम्म जात मात्र हैन बर्ण नै फरक गर्दा एकदम राम्रो. cooss गर्दा T 21 बच्चा त हुदैन नै साथ साथै नस्ल मा सुधार भएर अती तेज बच्चा जन्मिने धेरै सम्भावना हुन्छ .

हेटोउडे ब्रो को अहिले समम पाचौ वा छै ठौ छोरा छोरी भै सक्ने बेलामा खोजि खोजि गतिलो उत्तर ( बहुतै जायज ) दिनु भएको छ गुरुवा ले , भबिस्यमा बच्चा भयो वा कसैको हुने वाला छ भने न्वारन र चिना बनाउन गुरुवा लाइ भने अबस्यनै सम्झनु होला | याउरे फ़्याउरे लाइ कर्मकाण्ड लगाउन ठिक हुदैन पनि वहाले नै भन्नु भएको हो है |