Any mantras that can increase concentration or absorption of knowledge?
In Hinduism Saraswati is goddess of knowledge, music, art, wisdom, and learning etc. So its very appropriate to worship her before starting to learn some new skill . Similarly we can also pray to her before starting our daily studies etc. to get her blessings in right understanding of topic , memory etc. which is useful in studies.
Below is simple and easy Devi Saraswati Mantra for anyone to recite before starting of studies.This mantra is part of sarasvati dhyAnam.
सरस्वति नमस्तुभ्यं वरदे कामरूपिणि ।
विद्यारम्भं करिष्यामि सिद्धिर्भवतु मे सदा ॥7 ||
Saraswati Namasthubhyam Varade Kamarupini
Vidyarambham KarishyamiSiddhir Bavathume Sadha
Salutations to Devi Saraswati, Who is the giver of Boons and fulfiller of Wishes, 2: O Devi, when I begin my Studies, Please bestow on me the capacity of Right Understanding, always.
Start praying Ganapathi before doing any work. Well begun is half done. Then pray to Guru Dhanshinamurthy and Goddess saraswthi. It'll increase your concentration.