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NUS: Department of Mathematics
Ph.D. Qualifying Examination (PhD QE)

Important Dates | Objective | Format

Topics | Sample Papers | Registration

 

Important Dates

To sit for exam in

Submit application by

Semester 1, 2009/10

5pm, 5 Jun 2009

(End of week 20 in Semester 2 of the previous academic year)

Semester 2, 2009/10

5pm, 6 Nov 2009

(End of week 12 in Semester 1 of the same academic year)

   

Exam

Exam date in Semester 1

Exam date in Semester 2

Paper 1

17 Aug 2009

18 Jan 2010

Paper 2

19 Aug 2009

20 Jan 2010

Paper 3

21 Aug 2009

22 Jan 2010

Papers 1, 2 and 3 are always held on Monday, Wednesday and Friday, respectively, in week 2 of a semester. If the exam day falls on public holiday, it will be rescheduled.

 

 

 

Objective

To ensure that the Ph.D. candidate has sufficient background and breadth in mathematics for him to embark on his research.

 

All new graduate students are admitted to the Graduate Programme (by default). Students who are interested in the Ph.D. degree must pass the Ph.D. QE within stipulated duration before they are allowed to convert or upgrade from Graduate Programme to Ph.D..

 

Graduate students who fail the Ph.D. QE and those who choose not to take the Ph.D. QE will complete the requirements for the M.Sc. degree.

 

Example:

  1. A student with only an honours degree who wishes to pursue an M.Sc. degree would complete the requirements for an M.Sc. degree. He/she need not sit for the Ph.D. QE.

  2. A student with only an honours degree who wishes to pursue a Ph.D. degree directly would have to pass the Ph.D. QE within stipulated duration. Upon passing the examination and successfully converting to the Ph.D. programme, he/she would complete the requirements for a Ph.D. degree. However, he/she will not get an M.Sc. degree. If the student fails the Ph.D. QE, he/she would complete the requirements for an M.Sc. degree instead. 

  3. A student with M.Sc. degree who wishes to pursue a Ph.D. degree would have to pass the Ph.D. QE within stipulated duration. Upon passing the examination and successfully converting to the Ph.D. programme, he/she would complete the requirements for a Ph.D. degree. If the student fails the Ph.D. QE, he/she would complete the requirements for an M.Sc. degree instead. This implies that the student may eventually get two M.Sc. degrees. 

Note that for example 3, if the student already holds an M.Sc. degree in mathematics from NUS, he/she will not be allowed to complete another degree in the department.

 

 

 

Format

There are two components for the Ph.D. QE, a comprehensive examination and qualifying examination. A student has to pass both the comprehensive (written) and qualifying (oral) examinations. The comprehensive examination assesses the student's background while the qualifying examination evaluates his/her suitability and preparation status for research at Ph.D. level.

 

COMPREHENSIVE (WRITTEN) EXAMINATION

  1. There are three written papers: Paper 1 (Algebra), Paper 2 (Analysis) and Paper 3 (Computational Mathematics).

  2. Each paper lasts for three hours.

  3. Papers 1, 2 and 3 will be held on Monday, Wednesday and Friday in week 2 (academic calendar) of every semester. An examination will be rescheduled if it falls on a public holiday.

  4. A candidate is only allowed at most two attempts per paper within the stipulated duration for completing Ph.D. QE.

  5. A candidate may choose to sit for one, two or all three papers in one semester, subject to (4) above.

  6. A candidate must register for the Comprehensive (Written) Examinations by the stipulated closing date. During registration, he/she has to indicate the paper/s to be attempted.

  7. Registered candidates will be informed of the examination time and venue, via email, nearer the examination dates. 

  8. No changes are allowed for the choice of paper/s after registration is closed.

  9. A candidate will be informed of the result (pass/fail) for each paper.  If a candidate fails a paper, he/she may opt to be re-examined on the same paper or the one that has not been chosen in the first attempt, subject to (4) above.

  10. A candidate is considered to have passed the Comprehensive (Written) Examinations when he/she has passed at least two out of the three papers within the stipulated duration for completing Ph.D. QE.

  11. A candidate who wishes to retake a paper after the release of results must register by the stipulated closing date.

 

QUALIFYING (ORAL) EXAMINATION

  1. A candidate is invited to register for Qualifying (Oral) Examination only after he/she has passed the Comprehensive (Written) Examination.

  2. A candidate is required to present a 45-minute talk on his/her field of research.

  3. After the talk, the candidate will be interviewed by a panel of three examiners in the field of his/her research. The panel will consist of the candidate's thesis advisor, a staff member nominated by the department and a member from the graduate programme committee.

  4. In assessing the oral presentation, the candidate’s knowledge of the research area in a broad sense will be emphasized. Thus, in addition to a good presentation, a candidate is expected to demonstrate a good understanding of a broad range of topics in the chosen area of research.

  5. In the event that the candidate is a new incoming student without a pre-assigned supervisor, the department will appoint another staff member to sit on the panel.  

 

 

Topics

PAPER 1 - ALGEBRA

Syllabus

  • Sets: Cardinals, ordinals. Countability. Zorn’s Lemma.

  • Linear algebra: Finite-dimensional vector spaces, bases. Tensor product. Isomorphism of Mn(F) and End(Fn). Orthogonality, examples of classical groups. Diagonalization, Cayley-Hamilton theorem, spectral theorem, Jordan canonical form.

  • Group theory: Significance of classification of finite simple groups. Central and derived series. Structure of finitely generated abelian groups. Group presentations. Representations of finite groups.

  • Ring and module theory: Euclidean domain, principal ideal domain, unique factorization domain. Polynomial rings, reducibility. Noetherian rings, Hilbert basis theorem. Some noncommutative rings, e.g. matrix rings. Free and projective modules. Exactness.

  • Field theory: Fundamental theorem of algebra, algebraic closure. Classification of finite fields. Examples of Galois groups.

  • Category theory: Examples of categories, functors, natural transformations, adjoint functors.

Suitable textbooks

  • G D Crown, M H Fenrick & R J Valenza, Abstract Algebra, Marcel Dekker (NY, 1986)

  • A I Kostrikin, Introduction to Algebra, Springer Universitext (NY, 1982)

Suitable reference books

  • T W Hungerford, Algebra, Springer Graduate Texts in Math 73 (NY, 1974)

  • S Lang, Algebra, Springer (NY, 2002), rev. 3rd ed.

 

PAPER 2 - ANALYSIS

Syllabus

  • Part I: Advanced Calculus

  1. Properties of the reals such as Bolzano-Weierstrass, Heine-Borel and equivalent of norms in Rn.

  2. Differential calculus of Rm valued functions on subsets of Rn. Continuity and uniform continuity, differentiability, partial derivatives, Jacobians, implicit and inverse function theorems.

  3. Differential equations: existence and uniqueness theorem of initial value problems.

  4. Infinite sequences and series of numbers and functions. Absolute and uniform convergence, equi-continuity, Arzela-Ascoli theorem, Weierstrass approximation theorem.

  5. Riemann and Riemann-Stieltjes integrals, fundamental theorem of Calculus.

  6. Line integrals, surface integrals, differential forms. The theorems of Stokes and Green and the divergence theorem. Change of variables in multiple integrals.

  7. Metric spaces, completeness, limit and continuity.

  •  Part II: Real Analysis

  1. Functions of bounded variation and absolutely continuous function.

  2. Definition and elementary properties of Lebesgue measure.

  3. Borel measures, measurable functions and simple functions.

  4. Lebesgue integral and its elementary properties.

  5. Convergence theorems.

  6. Various types of convergence such as almost everywhere, in measure, in mean.

  7. Multiple integrals and changing the order of integration (Fubini’s theorem).

  8. Lebesgue’s differentiation theorem, Vitali’s covering lemma.

  9. Basic properties of Lp spaces, such as density of C¥ functions, approximation identities, Riesz representation theorem.

  10. Hilbert space and its basic properties.

  • Part III: Complex Variables

Cauchy-Riemann equations. Analytic functions. Contour integration. Cauchy integral formula. Taylor series. Residues and poles. Laurent series. Isolated singular points, removable/essential singularities, poles, residues, residue theorem, improper real integrals and their evaluation using the residue theorem. The argument principle. The open mapping theorem and the maximum modulus principle. Conformal mapping and linear fractional transformations. Harmonic functions.

 

Remarks

The paper will test more on content instead of tricks. Students are usually expected to score at least 60% of the total mark in order to pass the paper.

 

Recommended textbooks

  • (For Part I of this syllabus) Walter Rudin: Principles of Mathematical Analysis (first 10 chapters), 3rd edition, McGraw Hill

  • (For Part II of this syllabus) H.L. Royden: Real Analysis, 3rd edition, Macmillan

  • (For Part II of this syllabus) R. Wheeden, A. Zygmund: Measure and Integral: An Introduction to Real Analysis, Marcel Dekker

  • (For Part III of this syllabus) James W. Brown, Ruel V. Churchill: Complex Variables and Applications, 7th edition, McGraw Hill

 

PAPER 3 - COMPUTATIONAL MATHEMATICS

Syllabus

  • Fundamentals of Computational Mathematics

    • Approximation theory:  polynomial interpolation; piecewise polynomial interpolation; orthogonal polynomials; least squares approximation

    • Numerical integration: trapezoidal rule, Simpsons rule and  Newton-Cotes formulas; composite trapezoidal rule and Simpsons rule; Richardson extrapolation and Romberg integration

    • Matrix computation: matrix norms and vectors norms; direct and iterative methods for linear system (basic and Krylov subspace iterative methods); eigenvalue problem; QR factorization; singular value decomposition; linear least squares problem; Iterative mthods for nonlinear systems: fixed point methods, Newton’s method;

     

  • Numerical Solution of ODEs and PDEs

    • For initial value problems: Runge-Kutta methods; one-step methods; multi-step methods; consistency, stability and convergence

    • For two-point boundary value problems:  shooting and finite difference methods

    • Finite difference discretization for Poisson’s equation, heat equation and wave equation; consistency and stability analysis

     

  • Optimization Theory and Computation

    • Optimization theory: convex sets, hulls, cones and polar cones; convex functions; subgradients; KKT-optimality conditions; Lagrangian dual problems; weak and strong duality theorems

    • Numerical optimization: Newton's method and conjugate gradient methods for unconstrained optimisation; exterior penality function methods; Barrier function methods; Methods of feasible directions

 Recommended textbooks

  • Richard L. Burden and J. Douglas Faires, Numerical Analysis, 8th edition, Thomson/Brooks/Cole, 2005.

  • L.N. Trefethen and D. Bau, III, Numerical Linear Algebra, SIAM, 1997.

  • G.D. Smith, Numerical Solution of Partial Differential Equations: Finite Difference Methods, 3rd edition, Oxford University Press, 1985.

  • J. Nocedal and S.J. Wright, Numerical Optimization, 2nd edition, Springer, 2006.

 

 

 

 

Sample Papers

Algebra  |  Analysis 1  |  Analysis 2  |  Computational Mathematics

 

 

 

Registration

Download registration form here.

 

Completed registration forms should be returned to the department before the registration deadline by fax (+65-67795452) or email (AskMathPG@nus.edu.sg) or in person at the general office.

 

 

 

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Last modified on
01 Jun 2009 by Department of Mathematics