The Drop in String Citations (and raw output too)

[Martin]

In looking over the Spires Citation Database for physics papers

I've noticed a remarkable drop in citations of recent string theory papers.

 

this is for all kinds (string, brane, braneworld cosmology, M-theory) of stringy research. citations by other papers are one possible measure of the quality of research and there has been a surprisingly sharp decline

 

for definiteness I take 'recent' to mean the preprint appeared in the past 4 years so at end 2000 papers appearing in years 1997-2000 are recent.

 

In year 2000 there were 9 stringy research papers that garnered 125+ citations.

 

In year 2003 there were only 4 such papers!

 

And the numbers are telling

In 2003 the 4 recent highly cited papers got: 198,135,134, 125 citations.

In 2000 the 9 recent highly cited papers got: 498, 446,397, 347, 316 268,191,164,131 citations

 

Caveat: you cant tell anything for sure about the longterm validity of a research line. But if you go by appearances you might think that in the Good Old Days when string theorists were really string theorists there were a lot more landmark breakthrough by more active innovative people who got a lot more citations from their colleagues. Now the raw output rate and also the citability quality of research seems to be dwindling.

 

In terms of raw quantity (not citation quality) there were a lot fewer stringy research papers written in 2003 than in 2000 or 2001.

Again this covers all the categories across the board (string, brane, braneworld, M-theory etc.) The decline in raw numbers of papers could have other reasons (from the quality decline) so I will segregate discussion of it in a separate thread of its own

 

I will get some Spires links so anyone interested can check this out for themselves. Spires HEP database is maintained by Stanford/SLAC. It's a real useful resource.

 

Meanwhile, what to make of this sharper-than-expected drop-off? Is it going to bounce back or is the field in enough trouble that one would expect the decline to continue next year? (so far 2004 output has been lower even than in the same timeperiod in 2003, but we dont have any data on citations)

[Martin]

If you would like to see the String-related research papers available online at arXiv, listed by year, here are links to the arXiv search engine

 

(papers whose abstract summary has the keywords

string OR brane OR braneworld OR D-brane OR M-theory OR p-brane.)

 

Year 2000:

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/2000/0/1

 

Year 2001:

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/2001/0/1

 

Year 2002:

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/2002/0/1

 

Year 2003:

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/2003/0/1

 

Last twelve months (e.g. 1 June 2003 to 1 June 2004):

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/past/0/1

[Martin]

Here are some Spires links:

 

the general index:

http://www.slac.stanford.edu/library/topcites/

 

 

most-cited papers in 2003 for the whole database:

http://www.slac.stanford.edu/library/topcites/2003/annual.shtml

 

Here's where Spires breaks the 2003 citations down by field

 

astro-ph for astrophysics

gr-qc for general relativity and quantum cosmology

hep-th for high energy physics---theory

http://www.slac.stanford.edu/library/topcites/2003/eprints/index.shtml

 

----

[Aeschylus]

Martin, I can assure you that your figures are way too low, the actual number of stringyn papers in those years is nearer to the 1000's.

[Martin]

hi Aeschylus,

 

Im looking for the best numbers

which ones do you think are too low?

have you tried the arxiv search engine links?

please give me a sample of what you mean

[Martin]

Martin, I can assure you that your figures are way too low, the actual number of stringyn papers in those years is nearer to the 1000's.

 

What figures did I give that you want to say are too low?

 

Aeschylus, when you click on the links I gave you dont get a page that I prepared----you get a live search engine at arXiv

which does a keyword search (string, brane, braneworld, M-theory, etc)

for you at that moment.

 

arXiv has been called the most valuable info resource that the physics research community has, and rightly IMO----it is a great database

 

my guess would be in fact that the numbers you get are actually not too low but too high!

 

the keyword search picks up papers that say "string" in other contexts like string of symbols and cosmic string

 

you can glance over the list that the engine produces, when you click, and you will easily find a few papers that are not actually stringy physics-related.

 

but what I am curious to know is what numbers I have posted here you think are too low

[Aeschylus]

Because the total number of peer-reviewd papers on stringy theories is in the thousands each year, more than ten times the amount of something like LQG.

[Martin]

well we lost yesterday's posts

and Aeschylus had some perceptive things to say which are gone

and that's too bad

-----------------------

Spires HEP database (at the Stanford/SLAC Library and participating institutions)----the librarians decide what research papers are part of High Energy Physics and put them in the database

 

Each year Spires puts out a "top 40" or "top 100" list of the most highly cited papers in HEP as a whole

and also it puts out lists of highly cited papers in each of the ArXiv categories: hep-th, astro-ph, gr-qc (for general relativity-quantum cosmology) and so on.

 

there is a slight distinction to be made in that hep-th is a voluntary category chosen by the author(s) of the paper when they submit it to ArXiv.

they chose the designation. but the overall HEP data base of all research that the librarians think is High Energy Physics is not subject to the author's choice. The overall grouping is constructed by the librarians.

 

The 1999 overall Spires HEP topcite list, with only recent papers counted, had 24 papers which received 125+ citations.

Of these, 15 were recent string papers. (over 60 percent, a substantial percentage)

 

The number of citations these 15 recent string papers received that year were:

625, 464, 425, 285, 215, 202, 170 170, 167, 148, 146, 139, 137, 130, 126

 

In 2003, the overall Spires HEP topcites list, with only recent articles were included, had 20 papers which garnered 125+ citations. Roughly the same number, though a higher portion were from astrophysics. But in sharp contrast only 4 of the 20 were stringy type research (a smaller percentage than in 1999, 25 percent instead of 60 percent)

 

the numbers of citations for these 4 string papers were:

197, 135, 134, 125

---------------------------

So as a fraction of highly cited recent HEP papers, string goes down from 60 percent to 25 percent.

 

The number of highly cited recent string papers goes from 15 to 4

 

And the numbers of citations, for the 15 papers in 1999 and the 4 papers in 2003 are

 

625, 464, 425, 285, 215, 202, 170 170, 167, 148, 146, 139, 137, 130, 126

and, for 2003:

197, 135, 134, 125

------------------------------

 

Almost all research appears first in ArXiv so for the present purposes the appearance date is just given by the ArXiv number.

For definiteness 'recent' means the preprint appeared in the past 4 years so at end 2000 recent papers are those which appeared in years 1997-2000.

At yearend 1999 the recent papers are those appearing in the four years 1996 through 1999.

Likewise as of yearend 2003, those that appeared in 2000 through 2003.

-------------------------------

 

If we just consider the hep-th category in ArXiv, we get the same general picture. this time let's do the comparison between 2000 and 2003.

According to Spires, in year 2000 there were 9 stringy research papers in hep-th that garnered 125+ citations. Here are the numbers of citations each received:

498, 446, 397, 347, 316, 268, 191, 164, 131.

 

In 2003, by contrast, there were four recent highly cited stringy papers in hep-th, and they got:

197, 135, 134, 125 citations.

 

----------------

In 2003 it was, as you might guess, the same 4 papers. Topcited string papers in the hep-th category coincide with topcited string papers in the overall Spires HEP database.

----------------

 

It has been a sudden and dramatic decline, in the raw numbers of string research (as you can see by checking the ArXiv search engine)

and the citability quality, whatever that signifies (productivity in subsequent research terms, importance).

And as a percentage of the overall Spires HEP picture.

The shrinking importance of stringy research in the overall High Energy Physics scene was reflected in the annual HEP review by Michael Peskin.

I should get a link for that.

[Martin]

Here are the Spires links again, to which I'll add Michael Peskin's review of the High Energy Physics research picture:

 

the general index:

http://www.slac.stanford.edu/library/topcites/

 

most-cited papers in 2003 for the overall Spires HEP database:

http://www.slac.stanford.edu/library/topcites/2003/annual.shtml

 

Here's where Spires breaks the 2003 citations down by field

 

astro-ph for astrophysics

gr-qc for general relativity and quantum cosmology

hep-th for high energy physics---theory

http://www.slac.stanford.edu/library/topcites/2003/eprints/index.shtml

 

Michael Peskin's review for 2003

http://www.slac.stanford.edu/library/topcites/2003/review.shtml

 

He is a HEP librarian at SLAC/Stanford and he does the review every year.

In past years, like 2000 and 2001, he would put stringy research first, right after particle data.

Now he discusses cosmology first, and then several other areas of research, and then at the end discusses string---evidently because the field has declined.

 

why has it declined? can anyone shed some light on this.

[Martin]

Links to the ArXiv search engine (expanded list)

 

These are online papers whose abstract summary has the keywords

string OR brane OR braneworld OR D-brane OR M-theory OR p-brane.)

 

Year 1991:

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/1991/0/1

 

Year 1992:

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/1992/0/1

 

Year 1993:

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/1993/0/1

 

Year 1994:

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/1994/0/1

 

Year 1995:

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/1995/0/1

 

Year 1996:

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/1996/0/1

 

Year 1997:

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/1997/0/1

 

Year 1998:

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/1998/0/1

 

Year 1999:

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/1999/0/1

 

Year 2000:

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/2000/0/1

 

Year 2001:

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/2001/0/1

 

Year 2002:

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/2002/0/1

 

Year 2003:

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/2003/0/1

 

Last twelve months (e.g. 1 June 2003 to 1 June 2004):

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/past/0/1

[Martin]

Numbers of citations are a really different kind of data from

raw numbers of papers published.

 

A guy can publish 10 papers a year and if nobody references his papers

then his citation numbers are zero.

 

Citations counts how many other research papers referenced the given one. So it is one of the few objective measures of research quality.

 

If someone's paper has new ideas or gets useful results or is influential on the research that comes afterwards---is germinal in some sense---then it gets cited. It is like counting number of offspring in a biology experiment.

 

When a field of research goes stale there can be people who keep on writing papers in it because that is their carreer and what they do, but the papers are basically deadwood---they bear no future research. So it is good to watch both the raw output and the gauges of quality.

 

since it is two different things, I've put the raw output numbers in another thread and intend to focus on citations in this thread.

---------------

[Martin]

A day or so ago I learned of another database for publications in physics and related areas

 

http://adsabs.harvard.edu/physics_service.html

 

One of the sort options in this database is by citation-number: it ranks the papers it finds based on how many other papers cite them as reference.

 

A preliminary search hitting on occurrences of the words

brane, superstring, M-theory, D-brane

in the paper's abstract gave these numbers for 2000 thru 2003.

 

year    brane    superstring    M-theory    D-brane
2000    757      124              117          106
2001    969      131              113          114
2002    921      153              134          108
2003    800      133              113           89
decline  13%      13%              16%           18%

 

I put in the percentage decline in the last year---2002 to 2003

[Martin]

these are papers published in peer-reviewed journals

I think ADS stands for "astrophysics data system"

anyway it is NASA ADS and the site is at harvard.edu

there are some boxes to check at the top depending on

what type of journal you want the papers to be from

I checked "Physics/Geophysics" and "Astronomy/Planetary"

to get as many as possible

 

anyone who wants can reproduce these numbers

 

http://adsabs.harvard.edu/cgi-bin/nph-abs_connect?db_key=AST&db_key=PHY&aut_xct=NO&aut_logic=OR&author=&sim_query=YES&start_mon=&start_year=2002&end_mon=&end_year=2002&ttl_logic=OR&title=&txt_logic=OR&text=brane&nr_to_return=100&start_nr=1&start_entry_day=&start_entry_mon=&start_entry_year=&min_score=&jou_pick=ALL&ref_stems=&data_and=ALL&group_and=ALL&sort=SCORE&aut_syn=YES&ttl_syn=YES&txt_syn=YES&aut_wt=1.0&ttl_wt=0.3&txt_wt=3.0&aut_wgt=YES&obj_wgt=YES&ttl_wgt=YES&txt_wgt=YES&ttl_sco=YES&txt_sco=YES&version=1

 

http://adsabs.harvard.edu/cgi-bin/nph-abs_connect?db_key=AST&db_key=PHY&aut_xct=NO&aut_logic=OR&author=&sim_query=YES&start_mon=&start_year=2003&end_mon=&end_year=2003&ttl_logic=OR&title=&txt_logic=OR&text=brane&nr_to_return=100&start_nr=1&start_entry_day=&start_entry_mon=&start_entry_year=&min_score=&jou_pick=ALL&ref_stems=&data_and=ALL&group_and=ALL&sort=SCORE&aut_syn=YES&ttl_syn=YES&txt_syn=YES&aut_wt=1.0&ttl_wt=0.3&txt_wt=3.0&aut_wgt=YES&obj_wgt=YES&ttl_wgt=YES&txt_wgt=YES&ttl_sco=YES&txt_sco=YES&version=1

 

these two should get you the papers saying "brane" for the two years 2002 and 2003----it should show a 13 percent decline

 

if you say "string" it is not so meaningful because you get

papers about strings of ASCII characters and other kinds of

strings having nothing to do with string theory---all mixed in.

but nothing like that happens with "brane", so it is a better

way of keeping track of the trends.

 

there's a 13 percent decline from 2002 to 2003, in the first

two categories and somewhat more in the other two

this seems more reasonable to me than what i saw earlier

in the Spires database for 2003---that must still be under construction

 

for comparison here are the Stanford/SLAC spires numbers for

stringy publications 2002 and 2003. the number for 2003 may

not be final, they might be still cataloging, this is the only explanation

I can think of for its being so much less than that for 2002:

2002:

http://www.slac.stanford.edu/spires/find/hep/www?rawcmd=fin+k+string+model+or+matrix+model+or+membrane+model+and+date+2002&FORMAT=WWW&SEQUENCE=

 

2003:

http://www.slac.stanford.edu/spires/find/hep/www?rawcmd=fin+k+string+model+or+matrix+model+or+membrane+model+and+date+2003&FORMAT=WWW&SEQUENCE=

 

lately when i looked it showed a roughly 60 percent decline but that will presumably be reduced as they get closer to completing the catalog job

[Martin]

If a paper is going to get published it is typically a year or so after the preprint is posted on arXiv.

 

so the 13% decline in publications, 2002 to 2003, should have been foreshadowed by a similar decline at arXiv from 2001 to 2002,

the numbers measure different things and cannot be compared but the trend or percentage change can be. At the moment I see a 9 percent decline in stringy preprints here:

 

Year 2001:

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/2001/0/1

 

Year 2002:

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/2002/0/1

 

We dont have a final publication count for 2004, so the NASA ADS system doesnt help. But we can estimate what the decline in publication from 2003 to 2004 may be by comparing preprints in the preceding year.

 

At the moment I get a 13 percent decline in stringy preprints between 2002 and 2003 by comparing these two numbers:

 

Year 2002:

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/2002/0/1

 

Year 2003:

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/2003/0/1

 

So while we already know a decline in stringy research publication of roughly 13 percent, 2002 to 2003, we can forecast a decline of about the same size from 2003 to 2004

 

It is also possible to project somewhat into 2005 because the preprints are known for the first half of 2004. These continue the downwards trend.

 

Last twelve months (e.g. 15 June 2003 to 15 June 2004):

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/past/0/1

[jana]

In looking over the Spires Citation Database for physics papers

I've noticed a remarkable drop in citations of recent string theory papers.

 

this is for all kinds (string' date=' brane, braneworld cosmology, M-theory) of stringy research. citations by other papers are one possible measure of the quality of research and there has been a surprisingly sharp decline

 

for definiteness I take 'recent' to mean the preprint appeared in the past 4 years so at end 2000 papers appearing in years 1997-2000 are recent.

 

In year 2000 there were 9 stringy research papers that garnered 125+ citations.

 

In year 2003 there were only 4 such papers!

 

And the numbers are telling

In 2003 the 4 recent highly cited papers got: 198,135,134, 125 citations.

In 2000 the 9 recent highly cited papers got: 498, 446,397, 347, 316 268,191,164,131 citations

 

Caveat: you cant tell anything for sure about the longterm validity of a research line. But if you go by appearances you might think that in the Good Old Days when string theorists were really string theorists there were a lot more landmark breakthrough by more active innovative people who got a lot more citations from their colleagues. Now the raw output rate and also the citability quality of research seems to be dwindling.

 

In terms of raw quantity (not citation quality) there were a lot fewer stringy research papers written in 2003 than in 2000 or 2001.

Again this covers all the categories across the board (string, brane, braneworld, M-theory etc.) [b']The decline in raw numbers of papers could have other reasons (from the quality decline) so I will segregate discussion of it in a separate thread of its own[/b]

 

I will get some Spires links so anyone interested can check this out for themselves. Spires HEP database is maintained by Stanford/SLAC. It's a real useful resource.

 

Meanwhile, what to make of this sharper-than-expected drop-off? Is it going to bounce back or is the field in enough trouble that one would expect the decline to continue next year? (so far 2004 output has been lower even than in the same timeperiod in 2003, but we dont have any data on citations)

 

Your numbers (which I don't believe in any case) notwithstanding, if we were to judge what is going on in quantum gravity or theories of everything by these sorts of statistics, the conclusion would be that string theory is the only real game in town. I'm a student at university of toronto where a course in string theory is being offered to seniors and which I'm going to be taking next year. Other universities are now following suit. This I think says alot about the place string theory has earned for itself in physics. It sounds to me like you want to believe that string theory is sick, but this simply isn't true. Is there some specific problem about string theory that backs up what appears to be your intimations about it? If so, you should say it because one can justify any point of view by playing these sorts of games with numbers. Honestly, what your posting here just seems like a load of nonsense. There's an introductory book on string theory coming out soon. Maybe you should get a copy and read it before you waste more energy on this way of thinking about string theory.

 

Regards,

Jana

[Martin]

Your numbers (which I don't believe in any case) .. Maybe you should get a copy

Regards' date='

Jana[/quote']

 

Hi Jana, I see you are advising me to get a copy of B. Zwiebach's undergrad string text.

I am not going to offer you advice.

 

those numbers are good. the Stanford/SLAC library and the DESY library in Germany do most of the work on the Spires HEP database and it is the world's premier high energy physics database----especially for citations.

 

young faculty in physics depts are granted tenure on the basis of how many citations their papers get. it sounds a bit artificial but Spires is an integral part of the HEP scene.

 

and the do this annual review of "what's hot" in high energy physics research

 

I am just giving you Spires numbers

 

there has been a recognized change in the standing of stringy research and a shift of people out of HEP and into astrophysics

 

I am not involved or interested in what you as undergraduate study or dont study.

 

I'm offering this data in case it is interesting to someone. personally i find it interesting because it corresponds to what individual people say about the crisis inside the field----it is the quantitative side of what I hear that is anecdotal and qualitative

 

You ask me to say what is The Problem in stringy research and I cant sum it up in one thing. I hear a number of different doubts, worries and frustrations.

 

Also it might not do you any good for me to try to sum up what seems to be going on---it's a sea-change. It might not make any difference to you because if you dont even believe Spires HEP database-derived numbers then you probably would believe my best attempt to describe the situation.

 

so you are at the university of toronto? congratulations and good luck with your studies!

[jana]

so you are at the university of toronto? congratulations and good luck with your studies!

 

Thanks.

[Martin]

Also thanks to you for what seems a pretty cogent reponse in the other thread. It quickly got buried, so I will copy it here so i dont have to go scrolling for it. this is post #23 in the thread "What are the other dimensions for?"

 

My understanding is that these sort of reggeesque theories are deficient in a number of ways. Here are a few:

 

1) Since spacetime dimension is dynamical in them' date=' the associated fundamental degrees of freedom are not fixed in number and so these theories ultimately can't be unitary.

 

2) The most important thing we've learned about about quantum gravity (in fact GR all by itself apparently suggests this too, but I don't understand how) is that any quantum gravity theory must be holographic so they must not have fundamental degrees of freedom that are volume like.

 

3) They can't really explain the emergence of GR since the hilbert action is used as input.

 

4) Since they euclideanize to calculate the path-integrals, amplitudes reflect the microconfigurations that dominate the path-integral. So the reason that something that looks like 4d spacetime emerges isn't some deep heretofore unknown reason, but just that they only allow microconfigurations that look like the macroscopic configurations they want to result. Also, it is known in euclidean quantum gravity that when you "fine tune" the path integral this way, the theory in addition to seeming naive, usually ends up being nonunitary.

 

4) They predict new nonperturbative effects which must have descriptions at the semiclassical level and so must appear at energies below the planck energy. But this would require the theory give us a new constant of nature associated with this energy, but these theories never do which makes them seem more like toy models that have nothing to do with the physical universe.

 

5) Since as already mentioned, these theories quantize GR directly, they leave out the almost certain to be true possiblity that GR the hilbert action is just the lowest energy part of an action that contains other interactions that are suppressed at higher energies.

 

I don't think we should assume that spacetime is four dimensional. Instead, a quantum gravity theory should predict how many dimensions there are and then explain why if there are more than four dimensions, why we only see four of them. I think that String theory to some extent does both since it automatically imposes einsteins equations on the vacuum fields which determines the number of dimensions and also allows the idea that higher dimensions are either curled up too tightly to detect or interact only gravitationally as in braneworld scenarios. If we assume that all spacetime dimensions began life compactified, the question is why did only four of them decompactify. From what I understand string theory offers a large number of possible explanations for this, but I don't know any off hand.

 

Regards,

Jana

[/quote']

[jana]

Also thanks to you for what seems a pretty cogent reponse in the other thread. It quickly got buried, so I will copy it here so i dont have to go scrolling for it. this is post #23 in the thread "What are the other dimensions for?"

 

Actually, that was an incredibly sporting thing to do, so thankyou very much! But although I'm studying very hard, what I say should be checked carefully since I'm only an undergraduate and make mistakes all the time.

[Martin]

I hope you will expand on these points whenever you have time.

It's not my intent to rebut them (I'm not a debater really) I'd rather learn from them---especially the thinking underyling them.

 

it is the macroscopically apparent, or Hausdorff, or "effective" dimension which is allowed to vary. so perhaps it does not govern the number of degrees of freedom and the model is unitary after all.

 

John Baez was saying on SPR just the other day that it was unitary. I will try to find the link.

 

this is in partial response to your point 1)

 

maybe the Hausdorff dimension is just something one observes in the result after one runs the model---it is an observable rather than a determinant of the degrees of freedom

 

but in any case your point 1) and also the related point 2) are quite intriguing

 

your point 3) is entirely valid!----even I ( just a fascinated watcher of the Quantum Gravity scene) can see that you are right!

 

they put in the Einstein-Hilbert action (a simplicial version of it) "by hand" because they think GR has worked well and is probably about right and they want their quantum model to match it in the large-scale limit.

 

as a debating point you might come back with "but look string theory pulls the einstein equation out of the hat" or midair, or from behind your ear or something. which is definitely impressive

 

but I'm not debating about who's best right now so much as mulling over your points----I'm actually not worried by the fact that they use a quantum version of einstein-hilbert to build the model. they need some action formula and they thought that was the right action

 

there is a lot of experimental evidence that GR is right, so it figures

 

the question foremost in my mind is will the AJL approach work, will it have the gravity we know as largescale limit? they have another paper in the works

 

it is a barebones "minimalist" theory----quantum gravity with the least imaginable extra assumptions and structure, it seems---and if it works it should be a real breakthrough

[Martin]

jana's comment had some really interesting points---the thoughtfulness is almost as if the toronto undergraduate jana had asked a chief string-controversialist like Lubos Motl how he parries the AJL paper.

I am missing jana and hope she/he returns to contribute to the discussion.

 

the AJL paper is not exactly a Regge model but it is reggeesque.

 

-----exerpt from jana-------

 

"My understanding is that these sort of reggeesque theories are deficient in a number of ways. Here are a few:

 

1) Since spacetime dimension is dynamical in them, the associated fundamental degrees of freedom are not fixed in number and so these theories ultimately can't be unitary.

...

 

3) They can't really explain the emergence of GR since the hilbert action is used as input..."

 

-----end quote----

 

I started a thread about the AJL paper in Cosmology Forum

 

 

http://www.scienceforums.net/forums/showthread.php?t=4482

 

 

the AJL approach is to get a quantum model of the 4D geometry of the whole universe from beginning to end (if there is end)

and this should be done very simply as a weighted Feynmann-like average over all the paths it could take

 

and so in some sense the AJL model is "cosmology" because it is a quantum picture of the whole 4D thing

 

but also it is a quantum model of microscopic spacetime, where fields and particles live----so it is "modern/particle physics" too

Ambjorn Jurkiewicz Loll preprinted their papers including this one in

the hep-th part of ArXiv----hep-th is the "High Energy Physics-Theory" category.

 

http://arxiv.org/hep-th/0404156

 

so it really belongs in both cosmology and high energy physics

 

anyway I put the thread about AJL in cosmology forum

(this thread is about the decline of string theory which is a separate topic)

[Martin]

in string research it's fairly straightforward to show theres been a decline in quantity and quality---you just look at the Spires citation numbers (as a gauge of quality) and the NASA ADS numbers at the Harvard site show in overall numbers of published papers a decline of at least 13 percent 2002 to 2003, which continues at the same rate this year, if you go by arXiv as a leading indicator

 

so let's look at the flip side----there's been an increase in Non-string quantum gravity research. The numbers there will provide a contrast.

I've provided links so you can get the annual preprint counts directly from the arxiv search engine if you care to.

 

2001    92
2002   113
2003   129
LTM    138

 

2001:

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+AND+AND+loop+quantum+OR+cosmology+gravity+abs:+AND+AND+quantum+gravity+OR+OR+discrete+phenomenology+OR+canonical+nonperturbative+abs:+OR+OR+spinfoam+AND+spin+foam+AND+doubly+special/0/1/0/2001/0/1

 

2002:

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+AND+AND+loop+quantum+OR+cosmology+gravity+abs:+AND+AND+quantum+gravity+OR+OR+discrete+phenomenology+OR+canonical+nonperturbative+abs:+OR+OR+spinfoam+AND+spin+foam+AND+doubly+special/0/1/0/2002/0/1

 

2003:

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+AND+AND+loop+quantum+OR+cosmology+gravity+abs:+AND+AND+quantum+gravity+OR+OR+discrete+phenomenology+OR+canonical+nonperturbative+abs:+OR+OR+spinfoam+AND+spin+foam+AND+doubly+special/0/1/0/2003/0/1

 

 

Last Twelve Months:

http://arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+AND+AND+loop+quantum+OR+cosmology+gravity+abs:+AND+AND+quantum+gravity+OR+OR+discrete+phenomenology+OR+canonical+nonperturbative+abs:+OR+OR+spinfoam+AND+spin+foam+AND+doubly+special/0/1/0/past/0/1

 

this is just one of several possible boolean searches that can be done for non-string QG, by clicking on the link you will get the search function showing the keywords used, so I wont list them here.

 

anyway it is a more cheerful picture, even though field is small and has

less funding and fewer people

[Martin]

I noticed that the Wikipedia entries for string and LQG

give no inkling of these changes in the picture

It is possible that a degree of favoritism has crept in.

Lubos Motl, a string stalwart and moderator of sci.physics.strings,

has been one of the main authors of the Wikipedia pages

on these subjects.

[Dave]

I take it that you're of the opinion that string theorists are leading themselves up a dead end then?

[Martin]

I take it that you're of the opinion that string theorists are leading themselves up a dead end then?

 

nobody can say that, no one knows the future

and in some sense all rigorously conducted research is to the good

 

balancing research funding (where theory has gone for a long time without guidance from research) is a complex business

 

Peter Woit (a mathematician at Columbia who watches theoretical physics closesly) has a blog where people are discussing these issues (as well as just yakking and gossiping for fun)

 

the field is overhyped and overfunded just because of sheer momentum (a lot of people dont know how to do anything else) so it is due for a readjustment. meanwhile there is anecdotal and some statistical evidence that people are getting out of string (where the results have been poor lately) and even sometimes out of HEP and into things closer to astrophysics

 

some kind of shift is happening.

Woit's opinion may count for something, I cant say I have a definite opinion

here's Woits blog

http://www.math.columbia.edu/~woit/blog/

 

 

here's an arXiv bar graph showing hep versus astro-ph research

http://arxiv.org/Stats/hca_avg.gif

 

astrophysics used to be less than 1/7 of hep, in the heyday of string in the 1990s

but hep peaked in 2002 and has declined some (mainly the decline in string which was a major part of high energy physics research) and astrophysics is now approximately equal to hep.

look at the graph, picture worth a lot of words