1. Without indicates the absence of somebody.
I can't live without you.
Please don't leave without me.
2. Without means not having.
Pattern: verb + without + (any) noun
That young mother manages without any help.
We are without money this month.
3. Without means not using.
Pattern: verb + noun + without + noun
We did the crossword puzzle without a dictionary.
She can't read without her glasses.
4. Without means not performing an action.
Pattern: without + verb in gerund form
She passed the test without studying.
He left without saying good-bye.
without a doubt—certainly
She is without a doubt the best chairman we have ever had.
without fail—a demand or promise to do something Be here at six A.M. without fail.
I will finish within three days without fail.
without ceremony—immediately and quietly
He took charge without ceremony and began to work.
that goes without saying—that is understood to be true
You will be paid well for your work; that goes without saying.
Famous Indian Scientists
Sunil Mukhi is an Indian theoretical physicist working in the areas of string theory, quantum field theory and particle physicsHe earned a PhD in Theoretical Physics in 1981 from the State University of New York at Stony Brook After spending two years at the International Centre for Theoretical Physics at Trieste, Italy, he returned to India where he has worked at the Tata Institute of Fundamental Research in Mumbai, India since 1984 In November, 2012 he joined Indian Institute of Science Education and Research, Pune as the head of physics departmentHis major publications deal with fundamental properties of string theories, and include the conformal invariance of supersymmetric twodimensional field theories which describe the worldsheet dynamics of strings, the study of supersymmetric solitons using index theorems, the discovery of a new duality between string theory and Mtheory, the identification of string networks as supersymmetric states and the discovery of a novel Higgs mechanism in the worldvolume theory of Mtheory membranes