The samskaras to be performed by a Brahmin is laid down in the Dharmasasthras. The procedures are basically the same, with some modifications depending on the region.
But when it comes down to such beliefs as the above stated prohibition, there are hardly any scriptural authority. The beliefs vary.
But let us analyze the reasoning behind such a prohibition.
We do talk a lot of Suddhi and Asuddhi. They went to the extent of even deciding the distance to be maintained by the various castes when encountering a Brahmin. We have done away with all the long back. When someone dies is the house you have Theetu (Aachowm). This is part of Asuddhi. Extending this further, during the 1 year period, you are considered ashuddha. With such a Assuddhi, you can not visit the temple.
Beliefs vary from region to region. The Kerala Brahmins believe that if there is Ashuddhi in the temple, GOD leaves the temple. If there is Ashuddhi in the house all the Good/Divine spirits will leave the house.
But we do not believe in such extreme shuddis.
I do belong to a school where there is extreme concepts of purity/impurity when it comes to Puja. But that is only for individual practices.
When a beloved person dies, the sorrow is great. This is the time one needs solace. People visit temples to pray and get solace. The Prohibition mentioned by you goes against this fundamental idea.
Ignore such outdated advice and visit the temples and pray. Offer Archana. What is needed is purity and devotion in your heart. Seek solace in GOD.
