It was a landmark in the history of Indian Mathematics when a century ago, on April 4, 1907,
late
Shri V. Ramaswamy Aiyer ,
a Deputy Collector in the services of the then Madras Province, founded India’s
first Mathematical Society, with twenty enthusiastic founding members and with its
Headquarters at Pune. The Society was then known as
`Analytic Club’ which was soon
changed to `Indian Matheamtical Club’.
In 1910, however, new revised Constitution
was adopted and the club acquired its present name, the
`Indian Mathematical Society’.
To day, the Indian Mathematical Society (IMS)
is the oldest and the largest Mathematical Society of the Country.
The objects of the Society is the promotion of Mathematical Study and Research.
Its central activity is to inspire and encourage researchers, educationists,
students and all the mathematics loving persons .
Professor B. Hanumantha Rao was the first President of the Society; from 1907 to 1912.
Discovery of Srinivasa Ramanujan – the greatest mathematical genius
of modern times in India.
When we pauses to reflect on Ramanujan’s life, we see that there were certain events
that seemingly were necessary in order that Ramanujan and his mathematics be brought
to posterity. One of these was V. Ramaswamy Aiyer’s founding of the Indian Mathematical
Society, for had he not launched the Indian Mathematical Society, the next necessary
episode, namely, Ramanujan’s meeting with Ramaswamy Aiyer at his office in 1910, would
also have not taken place. Ramanujan had carried with him one of his notebooks, and
Ramaswamy Aiyer not only recognized the creative spirit that produced its contents,
but he also had the wisdom to contact others in order to bring Ramanujan’s mathematics
to others for appreciation and support. The large mathematical community that has thrived
on Ramanujan’s discoveries for nearly a century owes a huge debt to V. Ramaswamy Aiyer
and the Indian Mathematical Society.
IMS Conferences
The First, Second and Third Conference of IMS were held respectively at Madras (1916),
Bombay (1919) and Lahore (1921). One pleasantly notes that the IMS had jurisdiction
beyond the boundaries of the present Indian State. The Fourth Conference of IMS was
organized at Pune in 1924. In those days the Conferences of the Society were organized
intermittently with a gap of more years than one. From 1951 onwards, the Conferences
of the Society are being organized annually every year.
The Silver Jubilee Celebrations, on the occasion of completion of twenty five years of
existence of IMS, were held at Pune on March 26, 1932 under the Presidentship of Wrangler
Principal R.P. Paranjape. It is at this conference that it was decided to start
the publication of another periodical, as a part of this Silver Jubilee Celebrations,
and accordingly the Society started a new Journal named The Mathematics Student in 1933.
The 25th (Silver Jubilee) Conference of IMS was held at Allahabad in 1959. It was
inaugurated by Late Pandit Jawahar Lal Nehru, the then Prime Minister of India.
The Annual Conferences of the Society are full of very enriching programmes such as
Plenary and Memorial Award Lectures by eminent mathematicians, several invited Lectures
and Symposia on current areas of research as also presentation of large number of research
papers by researchers from all over the Country including the
Paper Presentation Competition.
The details of the venue of past conferences can be accessed
in
conferences.
Centenary Year Celebrations
The Centenary Year Celebrations of the existence of the Society took place during
73rd Annual Conference of the Society held under the auspices of the University of Pune,
Pune in December 2007.
Prof. S.T. Yau (Fields Medalist), Prof. Richard Hamilton (Clay Award winner) and
Prof. S.R. S. Varadhan (Abel Prize Winner) delivered Plenary lectures during the Conference.
The Platinum Jubilee 75th Annual Conference
of the Society was held under the auspices of the Kalasalingam University, Krishnankoil,
Tamil Nadu, in December 2009. On this occasion,
a Commemorative Postage Stamp
on the
“Indian Mathematical Society”
was issued by the Department of Posts (Philately Division), Government of India
to mark the completion of the hundred years of the establishment of the Society.
All these years, the Society has motivated and inspired a very large number of budding
mathematicians, and thus has served a great cause of promoting Mathematics Education
and Research in the Country.
To mark the occasion of this Centenary Year, Special Volumes of the Journal
(The Journal of the Indian Mathematical Society, The Special Volume 1907-2007)
as well as of the Mathematics Student (The Mathematics Student, Special Centenary
Volume (2007)) were published.
Periodicals published by the Society
The Society publishes two periodicals–The Journal of the Indian Mathematical Society
( JIMS; The Journal ; ISSN 019-5839) and The Mathematics Student ( Math.
Student ; the Student ; ISSN 0025-5742) both of which are quarterly.
The Journal of the Indian Mathematical Society (ISSN 0019-5839):
* Only the research papers of high quality are published in the Journal.
From its very inception, the Society started publishing, `Progress Reports’. The First
Progress Report was published in September 1907. Till December 1908, in all, eight `
Progress Reports’ were brought out. From 1909 the `Progress Reports’ were rechristened
as Journal and it was published every two months till 1933. The First Editor of `
Progress Reports’ and later of the Journal of IMS (JIMS) was
M.T. Naraniengar
who continued till 1927 and nurtured it for twenty years. Later the Editorship of JIMS was
entrusted to
R. Vaidyanathswamy
who served as editor upto 1950. During his tenure of editorship, in 1934, the present
new series of JIMS were started and was turned into a quarterly Journal.
It was due to the hard work put in by these two pioneering editors that the JIMS established
itself as one of the leading international Journals, a position which it continues to hold
even today.
It may be noted that with great pride that
• 1911 volume of this Journal contains earliest contributions of the
great legendry mathematician Srinivasa Ramanujan. They were in the form of questions.
In fact a fifteen page paper entitled “Some properties of Bernoulli Numbers” contributed
by Ramanujan also appeared in the same 1911 volume of the Journal. In fact, he published
12 of his research papers in the Journal of Indian Mathematical Society.
• S. S. Pillai, another brilliant Indian mathematician, who almost
solved the famous "Warring Problem", published 23 of his research papers in the Journal
of Indian Mathemtical Society and 8 papers in the Mathematics Student.
The Mathematics Student :
At the time of the Silver Jubilee Celebrations on the occasion of completion of
twenty five years of existence of IMS in 1932, it was decided to start the publication
of another periodical and accordingly the Society started a new Journal, named
The Mathematics Student, in 1933 with A Narasinga Rao as its first editor.
A. Narsinga Rao worked as the founder editor almost single – handed with great devotion
for eighteen years (1933-1950) and placed it on a firm footing.
It may be noted with great pride that
• A conference, first of its kind in Asia, entitled "South Asian Conference
on Mathematical Education" under the directorship of K. Chandrasekharan was held at TIFR,
Bombay during Feb, 1956 in which mathematicians like M. H. Stone, G . Choquet,
H. Freudenthal and a host of other world mathematicians participated; the entire
Proceedings of the conference has been published in the Mathematics Student Vol 54 (1956).
Currently, the following is published in The Mathematics Student:
• the texts of Presidential Addresses, the Plenary talks and the Award Lectures
delivered at the Annual Conferences,
• the abstracts of the research papers presented at the Annual Conferences,
• the texts of invited talks delivered at the Annual Conferences,
• research papers, and
• the Proceedings of the Society’s Annual Conferences, Expository & Popular articles,
Book Reviews, Reports of the IMS Sponsored lectures, etc.
IMS Library
The Library of the Indian Mathematical Society was started in 1907 at the Fergusson
College, Pune with Wrangler Principal R. P. Paranjape as its first Librarian,
who served in this capacity from 1907 to 1922. In 1950, the Library was shifted to Madras
(Chennai), and is now housed in the Campus of the Ramanujan Institute for Advanced Study
in Mathematics, University of Madras, Chennai : 600 005
The Library receives many journals on Exchange basis and has a rich collection of back
numbers of reputed mathematical journals received from all over the world. The complete
catalogue of the back volumes of all the periodicals published by the Society as well as
those received in exchange by the Society and available in the IMS Library, Chennai, is
now displayed on the IMS website. There is a spate of request for xerox copies of
articles published in these journals and the Library attends to these demands promptly.
If a particular journal is not available in the IMS Library, the scholars/students are
requested to contact other Libraries where it is likely to be available providing them
with the addresses of those Libraries.
Academic Programmes at Annual Conferences
Memorial Award Lectures
During every Annual Conference of the Society, the following Memorial Award Lectures are arranged as a part of the Academic Programme (each Award Lecture is of one hour duration).
1. P.L. Bhatnagar Memorial Award Lecture (Instituted in 1987)
2. Srinivasa Ramanujan Memorial Award Lecture (Instituted in 1990)
3. V. Ramaswamy Aiyer Memorial Award Lecture (Instituted in 1990)
4. Hansaraj Gupta Memorial Award Lecture (Instituted in 1990)
5. Ganesh Prasad Memorial Award Lecture (Instituted in 1993); and delivered every alternate year).
These Lectures carry a token honorarium of Rs. 2500/- each along with a citation.
Further, as part of the Academic Programme, there may be
• Plenary lectures by eminent Mathematicians,
• Symposia on current topics,
• invited talks, and
• research paper reading sessions.
P.L. Bhatnagar Memorial Prize.
This Prize is awarded annually to the top scorer of the Indian team at the International
Mathematical Olympiad. It consists of a cash of Rs. 1000/- and a Certificate. The award
is presented during the Inaugural Session of the Annual Conference of the Indian
Mathematical Society.
Award of Various Prizes for Research Paper Presentations
In order to encourage and inspire the young and budding research workers, the Society
holds, during its Annual Conferences, a Special Session of Paper Presentation Competition
for various Prizes to be awarded to the best research paper presented. This Special Session
is held as a part of the Academic Programme with no other parallel session.
The Council of the Indian Mathematical Society, at its meeting held at the Kalasalingam
University, Krishnankoil – 626190 in December 2009, considered the inclusion of several
other mathematical areas and regrouping of the same for the Six IMS prizes, AMU Prize
and V M Shah Prize being awarded by the Society, and resolved that the following grouping
of mathematical areas for these prizes be implemented with immediate effect. Thus, from
now onwards, following will be the areas and the grouping for these prizes :
1. IMS Prize : Discrete Mathematics (Combinatorics, Graph Theory, Posets and
related areas).
2. IMS Prize : Geometry, Algebraic Geometry, Differential Geometry, Topology,
Algebraic Topology, and related areas.
3. IMS Prize : Measure Theory, Probability Theory,Stochastic Processes,
and related areas.
4. IMS Prize : Differential/Integral/Functional equations and inequalities,
Numerical Analysis and related areas.
5. IMS Prize : Solid Mechanics, Fluid Mechanics, Electro-magnetic Theory,
Magneto-Hydrodynamics, Astronomy,Astrophysics, Relativity
and related areas.
6. IMS Prize : Operations Research, Optimization, Computational Mathematics,
Information Technology, Biomathematics, History of Mathematics
and related areas.
A M U Prize : Algebra, Number Theory, Lattice Theory, Set Theory, Logic and
related areas.
V M Shah Prize : Real Analysis, Complex Analysis, Functional Analysis,
Harmonic Analysis, Approximation Theory, Special Functions
and related areas.
Three / Four judges are appointed by the Council for “Paper Presentation Competition” for
deciding the award of various Prizes. Each of these eight prizes listed above carries
a Certificate and a cash amount of Rs.1000/-.
Following conditions apply :
1. Only the Members of the Society are eligible for participation in the Competition.
2. The upper age limit of a candidate for participation in the Competition is
40 years as on December 31, of the respective year.
3. a) The paper to be presented for the competition has to be under single
authorship
b) Independent work at the post-doctoral level is preferred.
c) The work must have been carried out in India.
d) Stress will be on both, quality of research as well as performance
during the presentation.
Note : One who is already awarded a prize in a certain area in the past is not expected
to participate in the competition for the prize in the same area.
IMS Sponsored Lectures
To popularize Mathematics and to create awareness regarding the Society and its
activities in the Country, the Society has a scheme of Sponsored Lectures.
It provides a token support of Rs.1000/- to a number of Departments / Institutions
for organizing popular and semi technical lectures.
Membership of the Society
Life Membership Fees :
Rs.2000/- (US $ 1000/- for those residing outside India).
The Life Members of the Indian Mathematical Society with their mailing addresses
in India or the International Life Members are entitled to a FREE copy of
the Mathematics Student for their personal use (not for sale/resale).
They can subscribe the Journal at Rs.1500/- (US$ 35/-) for their personal use
(not for sale/resale).
Ordinary Annual Membership Fees:
Rs.200/- (US $100/- for those residing outside India).
Sessional Membership Fees :
Rs. 200/- (US $ 100/- for those residing outside India).
• Sessional Members are those who join the Society only for a particular Session.
They may contribute papers for presentation and / or participate in any of the
academic programmes held during the Session.
• Membership form is available on the IMS Website.
• Only members of the Society are entitled to participate in the Academic Programmes
or present their papers in the Conferences. In the case of joint authorship of a
manuscript, all the authors are required to be members of the Society.
News Letters
Two News Letters (March & August), in a year, are published by the Society.
More detailed information may be obtained by referring to the latest News Letter from
the IMS Website.
List of Life Members
The Complete List of the Life Members of the Society is available on the IMS website
along with their unique Membership Numbers. Members whose mails have been returned
undelivered are marked accordingly with a note in red along with their names on the
IMS website.
Society looks forward to their correct addresses.
For any additional information, IMS website be visited.
o o o o o
Sr.
No.
year
President
Secretary /General Secretary
Academic Secretary
Administrative secretary
Treasurer
Editor JIMS
Editor MS
The Librarian
1
1907-08
B. Hanumantha Rao
V. Ramaswamy Aiyer
No Office
No Office
K.J. Sanjana
M.T. Naranienger
No Office
R.P. Paranjape
2
1908-09
B. Hanumantha Rao
V. Ramaswamy Aiyer
No Office
No Office
K.J. Sanjana
M.T. Naranienger
No Office
R.P. Paranjape
3
1909-10
B. Hanumantha Rao
V. Ramaswamy Aiyer
No Office
No Office
K.J. Sanjana
M.T. Naranienger
No Office
R.P. Paranjape
4
1910-11
B. Hanumantha Rao
D.D.Kapadia
No Office
No Office
C. Pollard
M.T. Naranienger
No Office
R.P. Paranjape
5
1911-12
B. Hanumantha Rao
D.D.Kapadia
No Office
No Office
C. Pollard
M.T. Naranienger
No Office
R.P. Paranjape
6
1912-13
R.N.Apte
D.D.Kapadia
No Office
No Office
C. Pollard
M.T. Naranienger
No Office
R.P. Paranjape
7
1913-14
R.N.Apte
D.D.Kapadia
No Office
No Office
C. Pollard
M.T. Naranienger
No Office
R.P. Paranjape
8
1914-15
R.N.Apte
D.D.Kapadia
No Office
No Office
S. Narayana Iyer
M.T. Naranienger
No Office
R.P. Paranjape
9
1915
E.W.Middlemast
D.D.Kapadia
No Office
No Office
S. Narayana Iyer
M.T. Naranienger
No Office
R.P. Paranjape
10
1915-16
R. Ramachandra Rao
D.D.Kapadia
No Office
No Office
S. Narayana Iyer
M.T. Naranienger
No Office
R.P. Paranjape
11
1916-17
R. Ramachandra Rao
D.D.Kapadia
No Office
No Office
S. Narayana Iyer
M.T. Naranienger
No Office
R.P. Paranjape
12
1917-18
A.C.L.Wilkinson
D.D.Kapadia
No Office
No Office
S. Narayana Iyer
M.T. Naranienger
No Office
R.P. Paranjape
13
1918-19
A.C.L.Wilkinson
D.D.Kapadia
No Office
No Office
S. Narayana Iyer
M.T. Naranienger
No Office
R.P. Paranjape
14
1919-20
A.C.L.Wilkinson
D.D.Kapadia
No Office
No Office
S. Narayana Iyer
M.T. Naranienger
No Office
R.P. Paranjape
15
1920-21
A.C.L.Wilkinson
D.D.Kapadia
No Office
No Office
S. Narayana Iyer
M.T. Naranienger
No Office
R.P. Paranjape
16
1921-22
H. Balakram
D.D.Kapadia
No Office
No Office
S. Narayana Iyer
M.T. Naranienger
No Office
R.P. Paranjape
17
1922-23
H. Balakram
P.V. Seshu Iyer
No Office
No Office
S. Narayana Iyer
M.T. Naranienger
No Office
V.B. Naik
18
1923-24
H. Balakram
P.V. Seshu Iyer
No Office
No Office
S. Narayana Iyer
M.T. Naranienger
No Office
V.B. Naik
19
1924-25
H. Balakram
P.V. Seshu Iyer
No Office
No Office
S. Narayana Iyer
M.T. Naranienger
No Office
V.B. Naik
20
1925-26
H. Balakram
P.V. Seshu Iyer
No Office
No Office
S. Narayana Iyer
M.T. Naranienger
No Office
V.B. Naik
21
1926-27
V. Ramaswamy Aiyer
N.M.Shah
No Office
No Office
S. Narayana Iyer
M.T. Naranienger
No Office
V.B. Naik
22
1927-28
V. Ramaswamy Aiyer
N.M.Shah
No Office
No Office
S. Narayana Iyer
R. Vaidyanathswamy
No Office
V.B. Naik
23
1928-29
V. Ramaswamy Aiyer
G.S.Chowla
No Office
No Office
S.R. Ranganathan
R. Vaidyanathswamy
No Office
V.B. Naik
24
1929-30
V. Ramaswamy Aiyer
Mukunda Lal
No Office
No Office
S.R. Ranganathan
R. Vaidyanathswamy
No Office
V.B. Naik
25
1930-31
M.T.Naraniengar
Mukunda Lal
No Office
No Office
S.R. Ranganathan
R. Vaidyanathswamy
No Office
V.B. Naik
26
1931-32
M.T.Naraniengar
Mukunda Lal
No Office
No Office
S.R. Ranganathan
R. Vaidyanathswamy
No Office
V.B. Naik
27
1932-33
P.V.Sheshu Iyer
S.B.Belekar
No Office
No Office
S.R. Ranganathan
R. Vaidyanathswamy
No Office
V.B. Naik
28
1933-34
P.V.Sheshu Iyer
S.B.Belekar
No Office
No Office
L.N.Subramanian
R. Vaidyanathswamy
A. Narasinga Rao
V.B. Naik
29
1934-35
H.G.Gharpure
S.B.Belekar
No Office
No Office
L.N.Subramanian
R. Vaidyanathswamy
A. Narasinga Rao
V.B. Naik
30
1935-36
H.G.Gharpure
S.B.Belekar
No Office
No Office
L.N.Subramanian
R. Vaidyanathswamy
A. Narasinga Rao
V.B. Naik
31
1936-37
R.P. Paranjape
Ram Behari
No Office
No Office
L.N.Subramanian
R. Vaidyanathswamy
A. Narasinga Rao
R.P. Shintre
32
1937-38
R.P. Paranjape
Ram Behari
No Office
No Office
L.N.Subramanian
R. Vaidyanathswamy
A. Narasinga Rao
R.P. Shintre
33
1938-39
R.P. Paranjape
Ram Behari
No Office
No Office
L.N.Subramanian
R. Vaidyanathswamy
A. Narasinga Rao
R.P. Shintre
34
1939-40
R.P. Paranjape
Ram Behari
No Office
No Office
L.N.Subramanian
R. Vaidyanathswamy
A. Narasinga Rao
R.P. Shintre
35
1940-41
R. Vaidyanathswamy
Ram Behari
No Office
No Office
L.N.Subramanian
R. Vaidyanathswamy
A. Narasinga Rao
R.P. Shintre
36
1941-42
R. Vaidyanathswamy
Ram Behari
No Office
No Office
L.N.Subramanian
R. Vaidyanathswamy
A. Narasinga Rao
R.P. Shintre
37
1942-43
F.W.Levy
Ram Behari
No Office
No Office
L.N.Subramanian
R. Vaidyanathswamy
A. Narasinga Rao
R.P. Shintre
38
1943-44
F.W.Levy
M.R.Siddiqui
No Office
No Office
L.N.Subramanian
R. Vaidyanathswamy
A. Narasinga Rao
R.P. Shintre
39
1944-45
F.W.Levy
M.R.Siddiqui
No Office
No Office
A. Narasinga Rao
R. Vaidyanathswamy
A. Narasinga Rao
D.D. Kosambi
40
1945-46
F.W.Levy
M.R.Siddiqui
No Office
No Office
A. Narasinga Rao
R. Vaidyanathswamy
A. Narasinga Rao
D.D. Kosambi
41
1946-47
F.W.Levy
M.R.Siddiqui
No Office
No Office
A. Narasinga Rao
R. Vaidyanathswamy
A. Narasinga Rao
D.D. Kosambi
42
1947-48
M.R.Siddiqui
T. Vijayaraghavan
No Office
No Office
Ram Behari
R. Vaidyanathswamy
A. Narasinga Rao
D.D. Kosambi
43
1948-49
M.R.Siddiqui
T. Vijayaraghavan
No Office
No Office
Ram Behari
R. Vaidyanathswamy
A. Narasinga Rao
D.D. Kosambi
44
1949-50
A.Narasinga Rao
T. Vijayaraghavan
No Office
No Office
Ram Behari
R. Vaidyanathswamy
A. Narasinga Rao
D.D. Kosambi
45
1950-51
A.Narasinga Rao
T. Vijayaraghavan
No Office
No Office
Ram Behari
K. Chandrasekharan
C.N.Srinivasienger
T. Vijayraghavan
46
1951-52
T. Vijayraghavan
S. Mahadevan
No Office
No Office
Ram Behari
K. Chandrasekharan
C.N.Srinivasienger
T. Vijayraghavan
47
1952-53
T. Vijayraghavan
S. Mahadevan
No Office
No Office
Ram Behari
K. Chandrasekharan
C.N.Srinivasienger
T. Vijayraghavan
48
1953-54
Ram Behari
S. Mahadevan
No Office
No Office
C.N.Srinivasienger
K. Chandrasekharan
K. Chandrasekharan
T. Vijayraghavan
49
1954-55
Ram Behari
S. Mahadevan
No Office
No Office
C.N.Srinivasienger
K. Chandrasekharan
K. Chandrasekharan
C.T. Rajgopal
50
1955-56
Ram Behari
S. Mahadevan
No Office
No Office
G.L.Chandratreya
K. Chandrasekharan
K. Chandrasekharan
C.T. Rajgopal
51
1956-57
Ram Behari
S. Mahadevan
No Office
No Office
G.L.Chandratreya
K. Chandrasekharan
K. Chandrasekharan
C.T. Rajgopal
52
1957-58
V. Ganapathy Iyer
S. Mahadevan
No Office
No Office
G.L.Chandratreya
K. Chandrasekharan
K. Chandrasekharan
C.T. Rajgopal
53
1958-59
V. Ganapathy Iyer
S. Mahadevan
No Office
No Office
G.L.Chandratreya
S.M. Shah
S.M. Shah
C.T. Rajgopal
54
1959-60
B.S. Madhav Rao
S. Mahadevan
No Office
No Office
G.L.Chandratreya
S.M. Shah
S.M. Shah
C.T. Rajgopal
55
1960-61
B.N. Prasad
S. Mahadevan
No Office
No Office
G.L.Chandratreya
S.M. Shah
S.M. Shah
C.T. Rajgopal
56
1961-62
B.S. Madhav Rao
S. Mahadevan
No Office
No Office
G.L.Chandratreya
S.M. Shah
S.M. Shah
C.T. Rajgopal
57
1962-63
C.N. Srinivasienger
S. Mahadevan
M.S. Ramanujan
No Office
P. C. Vaidya
R.P. Bambah and P.L. Bhatanagar
R.P. Bambah and P.L. Bhatanagar
C.T. Rajgopal
58
1963-64
Hansaraj Gupta
Shanti Narayan
V.S.Krishnan
No Office
P. C. Vaidya
R.P. Bambah and P.L. Bhatanagar
R.P. Bambah and P.L. Bhatanagar
C.T. Rajgopal
59
1964-65
P.L. Bhatanagar
Shanti Narayan
V.S.Krishnan
No Office
P. C. Vaidya
R.P. Bambah and M. Venkatraman
R.P. Bambah and M. Venkatraman
C.T. Rajgopal
60
1965-66
P.L. Bhatanagar
Shanti Narayan
V. Krishnamurthy
No Office
P. D. Gupta
R.P. Bambah and M. Venkatraman
R.P. Bambah and M. Venkatraman
C.T. Rajgopal
61
1966-67
R.S. Verma
Shanti Narayan
V. Krishnamurthy
No Office
P. D. Gupta
R.P. Bambah and M. Venkatraman
R.P. Bambah and M. Venkatraman
C.T. Rajgopal
62
1967-68
R.S. Verma
Shanti Narayan
V. Krishnamurthy
No Office
P. D. Gupta
M. Venkatraman and T.P. Srinivasan
M. Venkatraman and T.P. Srinivasan
C.T. Rajgopal