Spherical Equilateral Triangle with Dirichlet Bounds

The region examined here is the Spherical Equilateral Right triangle under Dirichlet Boundary conditions. Side lengths are 1. This triangle was one of our test cases to determine the accuracy of MATLAB's finite element solver in spherical space and whether we could accurately assume that we could treat the remainder of the error as a portion of the geometric series. This is because this triangle is one of the regions for which the eigenvalue spectrum is known: the ith distinct eigenvalue is equal to 12+2(i-1)(7+2(i-1)), and has multiplicity i. It confirmed both that the MATLAB solver was very accurate, and that our estimate of the remaining error resulted in even more accurate values. Together with our other known cases, this triangle also helped us to determine that the accuracy of the built in solver begins to deteriorate after the first approximately 250 eigenvalues.

Here are the counting graphs for the eigenvalue spectrum, using the true values since the spectrum is known. The first approximately 1250 values were used here.

Here are the difference graphs for the eigenvalue spectrum, using the true values since the spectrum is known. The first approximately 1250 values were used here.

Below is the Eigenvalue spectrum for the Spherical Equilateral Right triangle. These are the calculated and predicted eigenvalues, accompanied by their true values.

Spherical Right Equilateral Triangle        
         
Refinement        
012345 PredictedTrue Value
12.1683294312.0426403112.010719412.0026850812.0006716912.00016795 12.0000002712
30.9284785930.2355391530.0592485230.0148443630.0037136830.00092862 30.0000015430
31.1081765730.2802485930.0704277730.0176403930.0044128330.00110342 30.000001830
58.8955553156.733921656.1844518656.046197956.0115562556.00288957 56.0000046756
59.6054503156.910784656.2287260556.0572764356.014326956.00358233 56.0000057556
59.8716563756.9775334756.2454275656.0614564356.0153724156.00384375 56.0000061756
97.1655389391.8110947390.4551623590.1140212490.0285245990.00713265 90.0000118590
98.8888762692.2347220190.5602570590.1402301190.0350720490.00876917 90.0000136590
99.7451887192.4530040990.6150046690.1539323290.0384989290.009626 90.0000149890
100.120809392.5527212990.6403619690.1603302290.04010490.01002774 90.0000161590
146.5160578135.6736273132.9242088132.2316375132.0579592132.0144937 132.0000252132
150.396585136.6381668133.162406132.2909241132.0727605132.0181925 132.0000283132
151.8003386136.9913554133.2514386132.3132341132.0783416132.0195881 132.0000306132
152.7219799137.2375397133.3146057132.3292106132.0823526132.0205922 132.0000324132
154.2562291137.5812818133.3955685132.3490457132.08728132.0218217 132.0000338132
209.8452718188.9625641183.7424285182.4360188182.1090486182.027266 182.0000427182
215.5270294190.4451412184.1138887182.5289008182.1322696182.0330712 182.0000508182
217.9216295191.1473197184.2916981182.5734324182.1434048182.035855 182.0000546182
219.6365374191.6068374184.4090894182.602986182.1508105182.0377078 182.000059182
221.5470387192.1535037184.5496542182.6384313182.1596953182.0399308 182.0000632182
224.9730984192.8072074184.6974653182.6744831182.1686547182.0421674 182.0000644182
285.8697669251.5330442242.8892147240.723271240.180915240.045237 240.0000735240
294.9869808253.9099551243.4817917240.8711334240.2178539240.0544696 240.0000833240
300.6125471255.5097422243.8823654240.971304240.2429019240.0607322 240.0000928240
303.9000771256.6030206244.1596423241.0407176240.2602611240.0650724 240.0000994240
308.6994311257.6188972244.4004996241.1002031240.2750923240.0687781 240.0001016240
313.3610857258.722834244.6655585241.165938240.2915036240.0728801 240.0001053240
315.6556743259.1945856244.7762824241.1930884240.2982551240.0745656 240.0001062240
377.1752132324.1895844310.5646367307.1432508306.2860086306.0715183 306.0001202306
393.583655327.9903958311.4786634307.3692117306.3423239306.0855852 306.0001238306
400.0517694330.4465249312.111723307.5285078306.3822122306.0955614 306.0001431306
402.5185491332.4574666312.6002264307.6494391306.4123752306.1030983 306.0001484306
406.292866332.9404826312.7634199307.6930636306.4234594306.1058804 306.0001542306
411.687984334.5584778313.1438758307.7860223306.4465562306.1116457 306.0001592306
418.9730439336.4970018313.5835102307.8933161306.4732197306.1183018 306.000163306
430.7204422337.0666135313.6719156307.9132699306.4781099306.1195194 306.000167306
491.8077795408.4055189387.0977316381.7755156380.4440347380.1110236 380.0001688380
496.9099078414.3922856388.5050989382.1213288380.530094380.1325128 380.0001732380
512.7054999416.9713718389.2423056382.310118380.5775528380.1443934 380.0002062380
518.5323187418.4070016389.7442224382.4442792380.6116458380.1529523 380.0002125380
521.3600585420.9901817390.2150354382.5517598380.6378713380.1594669 380.0002129380
532.7464694424.1083807391.0511427382.7635171380.6909808380.1727569 380.000219380
539.7732361425.2756987391.2051254382.7929143380.6977983380.1744286 380.000254380
554.4369168426.5258823391.6864998382.9233289380.7309859380.1827605 380.0002656380
562.7489759428.141522391.8846012382.9601416380.739424380.1848239 380.0002709380
619.9041543502.0255484471.9700807464.4921926462.6231624462.1558056 462.0002266462
640.9017982510.7164179474.0029141464.9910963462.7472892462.1867987 462.000235462
652.6430731515.2580691475.2887068465.3208557462.8302413462.207569 462.0002981462
657.6724004519.2867054476.2778224465.5659546462.8913624462.2228388 462.0003039462
661.0329873522.0433668476.97604465.7387859462.93444462.2336 462.0003053462
678.3458585525.098955477.7262024465.9233662462.980365462.2450685 462.0003081462
685.0848504526.7353983477.9331644465.9739376462.9931496462.2482763 462.0003092462
699.7968408529.2370197478.7911654466.1956041463.0488478462.2622154 462.0003274462
714.9483397530.4594106478.9890898466.2353199463.0582178462.264526 462.0003281462
734.6033839533.0751952479.6721898466.4030451463.0998018462.2748936 462.0003667462
753.623366607.6586177565.9044679555.4783325552.8699335552.2175171 552.0003453552
785.0139688616.9525915568.2660787556.0675661553.0171258552.2543083 552.0003851552
790.6582838625.8980313570.3611823556.5831811553.1455167552.2863715 552.0003869552
815.9635539630.9685466571.7107144556.9240132553.2309358552.3077398 552.0004112552
829.8350029637.2532804573.2936595557.3126894553.327573552.331864 552.0004192552
845.5707089638.8346217573.701333557.4211634553.355176552.3387958 552.0004327552
856.5884465642.4156836574.4607284557.5970218553.3982143552.3495 552.000445552
884.7004889645.0323671575.2862725557.8133033553.4528449552.3631883 552.0004556552
903.5438483648.0584133576.0658076558.0061067553.5009398552.3752072 552.0004702552
929.8132655651.2318335576.593845558.1265734553.5304296552.3825449 552.0004709552
935.0324134653.1520476577.2702858558.299646553.5737482552.3933713 552.000481552
951.9217088728.4651789669.4776588654.8646942651.2161774650.3040609 650.0004418650
958.9666729742.7091014673.0657339655.7520233651.4372289650.3592714 650.0004483650
996.0809802747.8230787674.4534626656.1141544651.5288911650.3822608 650.0004838650
1029.396911754.3605455676.2224938656.5541889651.6386123650.4096673 650.0005379650
1037.405113762.1948517678.5136408657.1374746651.7849542650.446283 650.0005698650
1061.601577766.985072679.4341319657.3618422651.8407964650.4602314 650.0005784650
1070.687268773.4227124680.937476657.7219022651.9297613650.4824063 650.0005846650
1093.290237776.4215143681.4946163657.8485669651.9606513650.4900826 650.0006207650
1109.99435782.2108579682.8046436658.1567049652.0363692650.508928 650.000639650
1151.939334784.0849142683.6485597658.3940032652.0972967650.5242604 650.0006753650
1180.202107786.2370317684.526181658.58508652.1435619650.535739 650.0006784650
1197.484159789.7596777684.6442026658.6719518652.1687006650.5422331 650.0008258650
1224.033964861.6767398781.9736009762.470469757.6165303756.4040813 756.0004299756
1239.169686884.0644704787.1829691763.7400848757.9318758756.4827912 756.0004896756
1255.48831885.9412567788.4253999764.1033225758.0260986756.5065633 756.0005844756
1269.856489893.9818052791.0660726764.7808747758.1963111756.5491656 756.0006469756
1306.208467902.2589784793.2891942765.3543472758.3409268756.5853962 756.0007059756
1308.957773908.4790535794.8640344765.7378767758.4360093756.6091135 756.0007509756
1347.802629919.142321797.1386621766.2648894758.5649809756.6411782 756.000796756
1362.754634919.7703535797.5049379766.3619313758.5895929756.6473576 756.0008397756
1392.28707928.0491466799.4507456766.8191725758.7018809756.6753001 756.0008752756
1410.491865930.1267511799.951079766.98005758.7442533756.6860287 756.0009011756
1448.290425937.3817682801.5068498767.3626389758.8399696756.7099696 756.0009498756
1509.31387945.1075088803.0181757767.6726357758.9129311756.7279169 756.000989756
1545.297744947.7433474803.9488579767.9110743758.9728679756.7429325 756.0010273756
1564.4336231001.022778902.7149103878.179047872.0453357870.5113986 870.0007922870
1595.0576821030.224667910.0637037880.0001164872.4993765870.6248322 870.0008244870
1609.0223371040.907082912.3156311880.5461844872.6351085870.6587133 870.0008314870
1682.4775631057.41829917.3984849881.8226905872.9539062870.7383876 870.0008468870
1687.078291059.227886918.2292976882.0987825873.0277076870.7571396 870.000855870
1721.5687571076.23798922.271107883.0493226873.2610779870.8152072 870.0008885870
1747.3026741078.870905923.577123883.4226333873.3574034870.8394837 870.000901870
1763.2972411088.021479925.4398312883.8143262873.4502896870.8623825 870.0009379870
1821.0086491093.18218926.9433946884.1639611873.5362785870.8837954 870.0010426870
1858.182821098.844748927.188755884.2679823873.5649937870.8911406 870.0010868870
1873.4031711101.487039928.9936198884.6807397873.6654544870.916081 870.0011088870
1905.2352911109.262338931.1987411885.3039162873.8258814870.9564807 870.0013286870
1941.7575911111.212731932.3313378885.5290066873.8763612870.9687102 870.0013344870
2008.3228411121.880362933.329797885.758156873.9358886870.9837848 870.0013359870
2097.6608281168.8788171035.3695061002.790741994.6951028992.6736443 992.0007552992
2134.167731201.6578711044.2217961005.027454995.2556633992.8138861 992.000974992
2185.5589211208.5465671045.9670511005.439585995.3571567992.8391506 992.0009784992
01231.0672051052.5404121007.123459995.780023992.9449744 992.0009914992
01238.7129821054.0630281007.46504995.8636543992.9657868 992.0010842992
01257.8290721059.5560281008.87762996.218847993.0547066 992.0011153992
01260.1713061060.3944411009.098358996.2745637993.0686687 992.001133992
01272.5907871063.8619581009.905635996.4713185993.1175218 992.0011647992
01273.923531064.9329731010.232881996.5575808993.1393716 992.0011883992
01281.364551066.4320021010.565491996.638514993.1594767 992.0012629992
01287.5973091066.8301071010.611357996.6464511993.1612463 992.0013987992
01292.5664231069.8600351011.350591996.829231993.206801 992.0014493992
01304.1970351072.5639251012.038294997.000333993.2495224 992.001474992
01306.9775451073.040941012.202256997.047178993.2615933 992.0015125992
01311.5358411074.6970471012.56969997.1348951993.2832856 992.0015417992
01334.2569911175.1941251135.2916631125.3232991122.830894 1122.0008961122
01377.3597281186.968281138.252211126.0641291123.016149 1122.0010211122
01402.1869411190.9412611139.0979821126.2667731123.066261 1122.0011661122
01419.9965841197.360481140.819771126.7043641123.176106 1122.0011961122
01431.2411581200.586831141.5674051126.8872351123.221564 1122.0012391122
01451.8745261206.1862881143.0279581127.256211123.31405 1122.0012561122
01465.6821131210.0329581143.8587671127.4540781123.362873 1122.001361122
01467.6611111211.6364291144.4107191127.6029851123.400804 1122.0014271122
01476.6355211214.795131145.0789391127.7601611123.439446 1122.0015581122
01487.3287091216.708031145.5599181127.8821141123.470076 1122.001591122
01490.076581218.0312671145.8603831127.9539041123.487809 1122.0016441122
01496.8716311218.9143371146.1651561128.036721123.508925 1122.0017241122
01502.52641222.4191691147.0435361128.2539951123.563072 1122.0017431122
01509.1288441225.1161871147.6406521128.3985111123.598913 1122.0018111122
01510.761891226.0110251147.9618881128.4843161123.620694 1122.0020111122
01523.0573421228.2716111148.5976181128.6483241123.662007 1122.0021961122
01535.059641327.5456141276.7977191264.1949691261.048516 1260.0003341260
01574.3005011339.8429141279.9767211264.9962591261.249264 1260.0011251260
01602.7094191346.1022061281.3786051265.3354431261.333323 1260.0011471260
01626.4452621352.4433521283.0840361265.7713091261.442927 1260.0016381260
01637.3359451358.8454661284.6768521266.1647581261.540916 1260.0017631260
01657.4548771362.286191285.5810231266.3978871261.599711 1260.0018541260
01659.6488281368.1402591287.0237371266.7548631261.688682 1260.0019021260
01674.3239431371.3639021287.8518791266.9637391261.741034 1260.001991260
01687.4442611374.88981288.8190011267.2067731261.801803 1260.002111260
01697.8999021379.0521091289.544051267.3593711261.838188 1260.0021251260
01707.1878971379.5241031289.6942621267.4155911261.853404 1260.0021571260
01720.7378891381.2065241290.2227631267.5499041261.887139 1260.0022241260
01723.924691383.3423411290.7421551267.6808511261.920005 1260.0022861260
01729.4654291387.4255321291.7600611267.9295111261.981715 1260.0023741260
01734.0279381389.514751292.3114671268.0695751262.016887 1260.0025281260
01743.4591571391.9389441292.8564231268.2001121262.049133 1260.0025361260
01750.5844581395.2191451293.7401451268.4266561262.10615 1260.0026341260
01757.5202751489.9731221426.8902411411.2173121407.30407 1406.0008171406
01793.3577471503.8496761430.493791412.1276071407.532262 1406.0010531406
01837.8954851514.5655061432.8448091412.6923241407.671961 1406.0011851406
01848.1781741519.2460941434.3196561413.0816251407.770589 1406.001241406
01868.2733751529.4703281436.6250611413.6388171407.908656 1406.0012991406
01875.1750561530.010221437.0769031413.7748071407.944118 1406.0014571406
01887.4738171540.9641131439.6115221414.3921151408.097391 1406.0017591406
01898.5943741542.8851791440.1543451414.5318731408.132599 1406.002031406
01921.8617381548.2050811441.589161414.8979311408.224598 1406.0020461406
01924.2587321550.7650671442.146131415.0281741408.25648 1406.0022241406
01935.7256511552.3327251442.4513061415.0972131408.273267 1406.0023651406
01947.6969771557.254431443.6351451415.3845721408.344503 1406.0024531406
01952.8757891559.2508721444.1682781415.5321041408.382491 1406.0025771406
01962.0795641560.5349431444.5573511415.6325971408.407765 1406.0025951406
01969.9753541566.5621491445.8724051415.941541408.483699 1406.0026881406
01974.924461567.2666491446.1522021416.0227431408.504759 1406.0028131406
01990.0050181571.6699781447.1834931416.2698791408.565784 1406.0032251406
01992.5754531575.1183751448.0824671416.5014291408.624161 1406.0032391406
02013.5498141662.8500231585.5294371566.3725431561.592605 1560.0001571560
02025.645831680.4747331590.1939611567.5547041561.889177 1560.0006941560
02089.6434781694.887311593.2361221568.2755571562.066864 1560.0014921560
02096.5723961698.2669821594.4528191568.609031562.152117 1560.0015061560
02109.874251710.3491641597.4464881569.3509411562.337147 1560.0016211560
02126.6525351711.4389531597.7444731569.4319151562.357842 1560.0016231560
02132.12531720.8681251600.2416931570.0614991562.515547 1560.001831560
02135.2680921725.9889851601.4388481570.3496271562.58677 1560.002131560
02146.6127221733.8207051603.4332941570.856131562.713978 1560.0021861560
02165.9190711734.9453181603.7102431570.9225031562.730407 1560.0024441560
02172.8214591740.3463831604.919641571.2038891562.7992 1560.0024761560
02202.8555211743.0921131605.5122021571.3533661562.836775 1560.0027231560
02206.9649471747.1918381606.2363231571.526961562.879973 1560.0027851560
02218.2711291748.675841606.9515081571.7157661562.927547 1560.0030731560
02219.6119861753.6565531608.164081572.0169331563.002719 1560.0032751560
02231.6733031757.7306451609.3219361572.3030681563.073797 1560.0034791560
001759.63151609.8012971572.428921563.105869 1560.0036751560
001763.7218181610.4575971572.5713861563.140111 1560.0037021560
001767.4586751611.9102671572.9703051563.24209 1560.0038291560
001846.5337271752.8864941729.7080471723.92628 1721.9994451722
001867.6106021758.3110261731.075251724.268812 1722.0007891722
001885.5255971762.1310131731.9827641724.492689 1722.0014911722
001886.724631762.987211732.2430321724.560764 1722.0016851722
001902.7225751767.1210331733.2745691724.818351 1722.0022131722
001905.9368721767.7912871733.4317671724.856958 1722.0023311722
001915.6528311770.3045721734.065271725.01572 1722.0023421722
001924.0711141772.4465271734.5925021725.146799 1722.0025781722
001927.4529031773.5094931734.8909591725.223834 1722.0026341722
001935.2649981775.3198341735.3211481725.329774 1722.0030111722
001939.1206821776.3899691735.5834151725.394764 1722.0031311722
001942.1094031776.7930731735.6766471725.417879 1722.0031561722
001945.1176351777.7840671735.9282291725.480818 1722.0032361722
001948.9043371778.4930841736.0923511725.521195 1722.0033681722
001952.2672871779.07451736.2495761725.561487 1722.0035031722
001960.3709371781.3451711736.8039771725.698909 1722.0035251722
001963.2728581781.8182631736.9030681725.722499 1722.0035431722
001964.3110161782.6095141737.1343451725.782311 1722.003711722
001969.7039391783.5414461737.3412971725.83247 1722.0039151722
001977.6240781785.7831071737.9102051725.975091 1722.0059091722
002042.4525781929.2364221901.2878061894.320752 1891.9992771892
002062.0291111934.6485891902.6746741894.669645 1892.0001371892
002087.5529451940.5590371904.0972881895.021292 1892.0011641892
002091.6492791941.240741904.2820281895.069322 1892.0011981892
002106.4177781945.4362681905.3467281895.335999 1892.0016071892
002112.0888041946.8641491905.6993841895.423828 1892.0019281892
002121.9778391949.227341906.2834611895.569517 1892.0025021892
002134.2168481952.4460031907.0859521895.76973 1892.002661892
002136.67241953.2363731907.3107351895.828051 1892.0027521892
002148.0432831956.0724551907.9878081895.994877 1892.0028321892
002149.6458971956.4736721908.1222851896.03082 1892.0028641892
002157.6047011958.5153461908.5776711896.140998 1892.0031341892
002160.7454321958.8615591908.6989841896.173358 1892.0033721892
002163.9523171959.901591908.9158061896.225469 1892.0034231892
002166.2819231960.2007481909.046931896.261604 1892.0036971892
002172.7717231961.7177561909.3863811896.34397 1892.0039141892
002178.7035891963.9026031909.9567271896.487747 1892.0042861892
002182.7161271964.5679751910.108981896.52468 1892.0049871892
002185.5831241965.1996661910.2471171896.5585 1892.0057131892
002192.9230151966.8425981910.6304751896.652251 1892.0057751892
002200.437181968.8784331911.184311896.793678 1892.0058971892
0002113.6899182080.8947772072.722113 2069.9992272070
0002121.1363932082.7787952073.194647 2070.001182070
0002127.4222084.3264232073.57924 2070.0012612070
0002128.0731852084.4820292073.619101 2070.0016522070
0002132.1397612085.5301092073.882563 2070.0017692070
0002135.3552086.2885462074.069246 2070.0017912070
0002137.2166742086.7711952074.191016 2070.0025772070
0002141.2122062087.7816022074.444335 2070.0028682070
0002142.4065232088.0594362074.512334 2070.0031252070
0002145.0792882088.7323042074.680713 2070.0033082070
0002145.9830052088.9915032074.747931 2070.0033172070
0002149.2725372089.7557592074.93477 2070.0033782070
0002149.4560982089.8550272074.962661 2070.0034132070
0002150.042142089.9693612074.989651 2070.0036022070
0002151.5707352090.379762075.093567 2070.003852070
0002152.1551552090.4882422075.119643 2070.0040462070
0002153.6504162090.8688942075.214522 2070.0043412070
0002156.8431212091.6745812075.414966 2070.0047182070
0002157.1081952091.7300692075.429424 2070.0052042070
0002157.9707012091.9228162075.475912 2070.0053932070
0002159.7604522092.3446592075.579798 2070.0054082070
0002162.2766082093.0240862075.753094 2070.0066292070

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